Answer: Discovering unusual perspectives

This week's Challenges are all about finding information from an unusual perspective.  

One of the biggest problems people have when searching for information is that they get locked into thinking about their search in one particular way.  By asking these questions, I'm trying to make the deeper point that sometimes you have to have a different point-of-view.  

Literally.  

Let's look at the Challenges:  

1.  I was in Los Angeles (CA) the other day, and I happened to notice something unusual attached to the back of each letter on the famous "Hollywood" sign.  Once you see it, of course they'd need to have this on the back of each letter--but I'd never though about it before.  What's on the backside of each of the letters? 

It's an interesting point-of-view problem.  Literally.

Google Earth won't give you this;  neither Streetview nor satellite view in Google Maps will do.  What else can you do?

When I thought about this, I immediately thought about Google Images.  "Surely someone has taken a recent picture of these letters... and almost certainly from the backside as well."

This is a bit of knowing that there's a sub-culture of people who love to take pictures of things they're forbidden from visiting.  (Witness all of the picture of people you love urban exploring.)

My query was simple:

     [ Hollywood sign back ]

And here's what I got:

From this vantage point you can see that there's a support structure (which you'd expect) and a set of ladders to climb up each letter (which I did NOT expect).  I assume they're for maintenance, but the point here is that everything has multiple points-of-view.  It's not hard to search for them, but you have to keep your mind curious and remember this.

2.  The aurora borealis  (or aurora australis) is one of the most amazing sights on the planet.  When you look at it, you see vast sheets of colored, translucent drapes moving across the sky.  In appearance, it's just colored lights--but when seen from above, what shape are the Northern (or Southern) Lights?  Can you find a picture that shows the overall, planet-wide shape of the aurora? 

We've all see these pictures of the aurora--they're gorgeous (and I hope to see them in person one day).  They're generated when the charged particles from the sun strike atoms in Earth's atmosphere, causing electrons in the atoms to move to a higher-energy state. When the electrons drop back to a lower energy state, they create the glowing curtains of light we see as auroras.

But to figure out the pattern of the aurora on a planetary-scale, we have to find an image that's taken from WAY out in space.  

Here, my query on Google Images was: 

     [ deep space aurora ] 

but I ended up accidentally finding lots of science fiction images (who knew that "Deep Space" is the name of a science fiction television show AND a 1988 horror/science-fiction movie?).  

So I modified my query to pull up only reliable images: 

     [ deep space aurora site:nasa.gov ] 

this is our old friend site: being used to limit my results only to NASA.gov images. Even so, I had to look through a few images before finding this (click on the image to follow it back to NASA's web page): 

But notice that this isn't QUITE a picture of the aurora as it appears on Earth.  If you read the web page carefully, you'll find that this is a picture of the aurora in a composite image:  It wouldn't look like this from space without special filters, etc.  As the web page says:  "The IMAGE satellite captured this view of the aurora australis (southern lights) on September 11, 2005, four days after a record-setting solar flare sent plasma—an ionized gas of protons and electrons—flying towards the Earth. The ring of light that the solar storm generated over Antarctica glows green in the ultraviolet part of the spectrum, shown in this image. The IMAGE observations of the aurora are overlaid onto NASA’s satellite-based Blue Marble image. From the Earth’s surface, the ring would appear as a curtain of light shimmering across the night sky."  

3.  We know that some plants move to follow the sun.  Can you find a video of a sunflower following the sun?  How about some other plant?  What do they do to follow the sun across the sky? 

This was a slightly trickier question.  Since I already knew the word for "sun following" (it's heliotropic) I used that to find a video of a sunflower in motion with the query: 

     [ heliotropic sunflower ] 

It's not hard to find them.  (But be careful--there are at least a couple of animations of sunflowers that look good, but are completely synthetic!  Careful what you accept as evidence.)  

As I looked through the videos, I learned from the Indiana Dept. of Biology website that many people are under the misconception that the flower heads of the sunflower (Helianthus annuus) track the sun. When you see a field of cultivated sunflowers, the flower heads face in more-or-less the same direction. However, if you check out a field of sunflowers in the afternoon, it will be apparent that the flower heads are mostly facing east, where the sun rises each morning.  And if you look at them in the morning, they're still pointing east.  

Immature flower buds of the sunflower do exhibit solar tracking and on sunny days the buds will track the sun across the sky from east to west and by dawn the buds will have returned to face eastward, like the leaves in the movie above. 

So I modified my query to include: 

     [ immature sunflower heliotropic time lapse ] 

and found this video of immature sunflowers sun-tracking during the day. 

However, as the flower bud matures and blossoms, the stem stiffens and the flower becomes fixed facing the eastward direction. Flowers of the wild sunflowers seen on roadsides do not follow the sun and their flowering heads face many directions when mature. However, their leaves exhibit some solar tracking.

But that left me wondering:  What DOES a sunflower do during the day, if not tracking the sun?  

The query: 

     [ sunflower time lapse ] 

brought me the following very satisfying (and beautiful) video of a sunflower making small, fascinating movements during the day, but notably NOT tracking the sun! 

Unlike the sunflower flower, the flowers of some plant species track the sun across the sky from east to west. A good example of this is the alpine plant, the snow buttercup (Ranunculus adoneus).  Searching for a video for this lead me to this completely unexpected video of Arctic poppies following the sun during a full 24-day (when it never sets). 

Lovely. 

Search lessons:  

These weren't hard Challenges, but they're great examples of the deeper point that we searchers sometimes need to take a somewhat different point of view... and that it's often useful to think about what other points of view (from the back, from space, from a time-lapse) would be helpful in answering our Challenge questions.  

Hope you enjoyed this one!  

As always, 

Search on! 

Search Challenge (3/25/15): Discovering unusual perspectives

I'm back from my mini-break, back from diving in the Caribbean, rested and relaxed...

... and immediately heading out on the road again to teach search classes.  I'm traveling to DC to bring a bit of SearchResearch there.  Stay tuned for more Challenges coming from that part of the world.  (And not to worry--we'll have Challenges from Cozumel as well.  In just a bit.)  

First, I wanted to focus in a bit on finding "unusual perspectives," that is, finding answers to questions through images in ways that you might not have thought about.  

Today I have three questions, all of which can be answered, but the usual searches might not quite work, so you'll have to try something a bit different. 

1.  I was in Los Angeles (CA) the other day, and I happened to notice something unusual attached to the back of each letter on the famous "Hollywood" sign.  Once you see it, of course they'd need to have this on the back of each letter--but I'd never though about it before.  What's on the backside of each of the letters? 

2.  The aurora borealis  (or aurora australis) is one of the most amazing sights on the planet.  When you look at it, you see vast sheets of colored, translucent drapes moving across the sky.  In appearance, it's just colored lights--but when seen from above, what shape are the Northern (or Southern) Lights?  Can you find a picture that shows the overall, planet-wide shape of the aurora? 

3.  We know that some plants move to follow the sun.  Can you find a video of a sunflower following the sun?  How about some other plant?  What do they do to follow the sun across the sky? 

As always, be sure to tell us HOW you found the answer to the Challenge questions.  (And what did NOT work out for you?)  

Search on! 

Taking the week off...

As you could probably tell,
I've been a bit busy.  

This past weekend was the Learning At Scale 2015 conference in Vancouver.  I was one of the organizers, and as a consequence, my time was allocated from the moment I posted last week's Search Challenge until now.  (Which is why my answer was so late.  I've been running nonstop for a while.) 

But now, even as I write this, I'm sitting in an airport heading for the Caribbean.  Time to go diving again.  

So THIS is my plan for the week.  

My plan is to kick back, read a bit, and write a Search Challenge for next week.  

But this week?  Nah.  I need a break. I'm hitting the water later today.  

I'll be back.  Don't go away.  Take a mini-vacation yourself!  

-- Dan 

Answer: Is the fruit getting sweeter?

This week's question by Miguel Viterbo asked: 

We've heard rumors that farmers add sugar (or some kind of sweetener) to the irrigation of fruit. 

(1) Is this true? Does this actually work to make fruit sweeter? 

 (2) Should I be concerned?  Sugar is already hiding in so many everyday "non-sugar" foods (way more in the US than in Portugal, granted) that I don't want to take any more added sugar.  If it's really more sugar, how much more is it?  

When I first read this question, I immediately thought this sounds like an "urban legend" that could have some basis in fact.  How can we find out?  

Let's chat about strategy for a minute:  

I'd try a couple of different steps to answering this question.  I sat back for a second and thought about what I'm going to do.  Here's what I came up with... 


A.  First, check-assumptions about the question:  Maybe the presumption that "fruits have been getting sweeter over the past decade isn't true.  Is it?  

B.  Second, try a "first principles" approach:  If it's true that fruit is getting sweeter, then I'm going to do a back-of-the-envelope calculation to see if just adding sugar to an irrigation system makes sense.  How many pounds of sugar would you have to feed to a plant to make the fruit sweeter?  How would you dissolve it into the irrigation supply? 

C.  The simple approach:  Search on things like [ irrigation additives ] and explore how people decide what to add to irrigation systems.  I already know they add certain kinds of fertilizers, could they add something that acts to make fruit sweeter?    (Note here--I'm not assuming they're adding just sugar--it could be some kind of artificial sweetener or chemical that acts to increase total fruit sugars.)   In the process, I'm probably going to check out some agricultural schools to see what they teach farmers to put into irrigation systems, and I'm going to look at both row irrigation (where the water flows freely down channels through the fields) and drip irrigation systems (where a small water line is run directly to the base of each plant).  

Start here:  A.  First, check-assumptions about the question:   Let's begin with our assumptions.  HAS fruit been getting sweeter over the past 10 or 20 years? I started with the simple and obvious query: 

     [ fruit getting sweeter over time ] 

This is a long query--why did I add "over time"?  I added that to see if I could get articles that discuss the changes in fruit sweetness, and I would expect that phrase to appear in the text.  

I explored this for a while, finding a couple of articles, e.g., "Sugar high: Why your food is getting sweeter"  which includes the tidbit that a Cornell apple specialist denies that apples are getting sweeter over time, although a Times of London article (requires subscription) claims that food scientists are breeding fruits and vegetables to be sweeter, so our baseline understanding of what’s “naturally” sweet is changing. 

While I read a lot of articles here, all of them suggested that new, and improved varieties are probably making some fruits sweeter.  But, interestingly, none of the articles mentioned changes in irrigation practices.  

So it seems that some fruits have been getting sweeter, but so far, it seems to be slow changes over time with changes in new fruit varieties.  

Let's try our second approach... 


B. Try a "first principles" approach: Would adding sugar to irrigation water work to make the fruit sweeter?  

Let's consider oranges.  How many pounds of fruit will a single tree generate in a year?  

     [ pounds of fruit can an orange tree produce ] 

Which leads to multiple articles, the best of  which is from Texas A&M agriculture school.  "Home fruit production: Oranges" which has a good table of orange tree production as the tree ages.  At maximum production, a single Navel orange tree can produce around 100 pounds of fruit per year. 

Okay.. how much irrigation water will that tree need during the year?  My query: 

     [ how much water does an orange tree need per year ] 

leads to several articles, the best of which is from the University of Arizona agricultural school.  The article, "Irrigating Citrus Trees" tells us that each tree requires a different amount of water, depending on canopy size and the air temperature.  That makes sense... but what's the average?  There's a giant table in that article, when you boil it down, tells us that an average tree needs around 29 gallons / water / day during the growing season.  

If you produce 100 pounds of fruit and want to add sugar to the irrigation water to get a 1% increase in sugar to the fruit, you'll need around 1 pound of sugar to get into the fruit.  If you assume that 10% of the water delivered to the tree is then directed to the fruit, then the irrigation water needs to have 0.29 gallons of sugar, or 5 cups of sugar, to each tree for each day.  (Assuming drip irrigation.)  If you have 1000 trees, that's 5000 cups of sugar to add to your irrigation system each day to keep it at that level.  

1 cup of sugar weighs in at about 0.5 pounds.  So 5000 cups of sugar is around 2500 pounds of sugar each day.  That's a LOT of sugar to be sending out into the irrigation water.  

(And I can easily imagine the troubles with sugar-loving bugs, and problems that sugar-laden drip irrigation lines would cause.  It's seeming less and less probable.)  


C.  The simple approach:  Let's try the simplest query:  

     [ irrigation additives ]   [ irrigation supplements ]   [ "added to" irrigation ] 

Surprisingly, none of these worked especially well. I found lots of off-topic content, but little that led me directly to useful results.  

Now what?  

I know farmers sometimes add things to their irrigation--the question is, what do they call it?  What special terms do they use? 

To find out, I did a search for: 

     [ irrigation fertilizer ] 

and spent a little time reading around on farmer's web site, when I finally found an article on USDA.gov (the US agricultural department).  A ha!  Now I had an entire agricultural site to check out!  (How could I have forgotten them?)  And by reading the farmer articles, I discovered that additives are put into the irrigation system by means of injectors.  (That's the device that adds and mixes irrigation additives to ensure that the contents are mixed and put in at the right time and place.)  

     [ site:usda.gov irrigation injector ] 

leads to a LOT of articles--many about pest controls and fertilizer agents.  

And although I tried many queries to follow up on sweetening (or additional sugar) via irrigation and/or injectors, I didn't find anything. 

      [ site:usda.gov irrigation sweeten ]    [ site:usda.gov  irrigation sugar ]  

Not much. 

On the other hand, I DID learn that red-colored plastic film seems to make strawberries sweeter, and that there's a good deal of research to make sugar beets have more sugar.  

But I couldn't find anything about anything added to irrigation to make fruit sweeter.  

A few searches on: 

     [ breeding fruit sweet ] 

led to a large number of articles, many of which point out how active breeding programs have led to sweeter pineapples (such as the "Maui Gold" which is twice as sweet as its predecessor, introduced into Europe in 1996), sweeter strawberries, and sweeter apples.  

So while it's tempting to think that irrigation additives are making the fruit sweeter in taste, the more likely story is that farmers are using the fruits of agriculture breeders in their quest to constantly improve the fruit. 

Whether or not a hyper-sweet apple is to your liking is up to you.  (And there ARE regional preferences in what levels of sweetness and flavor make up a "perfect" apple, orange, or strawberry.)  

But I don't think they're adding anything to the water.... 


Search Lessons:  There are two big ones here.  

1.  Disproving something that's not happening is hard.  As you can tell, a lot of searches that do NOT find anything doesn't definitively close the case, but it does give pretty strong evidence.  The best thing to do here would really be to go talk to an orange farmer, or apple farmer and ASK.  But barring that, a complete sweep of all the different ways you can think of to ask the question.... that's about the best we can do.  Proving that something doesn't exist is always hard. 

2.  When your searches aren't working, look for something in the field that you KNOW you can find; go read there, and learn some language that can help.    That's what I did when I searched for [ irrigation fertilizer ].  I knew that was true.  And in the process of reading broadly in the topic I learned all kinds of terms and concepts that I could use to hone my search more effectively.  


Search on! 



____ 
Many thanks again to Miguel Viterbo.  This excellent question comes from him.  

Traveling!

The basketball ref hand sign for illegal traveling.

Okay, this was an error on my part.  

I'd forgotten that I'd be traveling today.  I'm flying up to Seattle, then driving on to Vancouver to attend the ACM "Learning at Scale" Conference. It's not optional--I really have to be there.  

But I'm busy from now (3:45AM) until at least 10PM tonight.  So I'm willing to bet I won't be able to write up my answer to this week's Search Challenge.  

That gives everyone an extra 24 hours.  So if you haven't chimed in yet with your idea about whether or not fruit is sweeter because of something they're doing with the irrigation water, now you've got an extra day.  

I'll be back tomorrow! 

Search on! 

P.S.  To be clear, I didn't forget exactly, but I thought I'd have time to write up the answer this morning.
          THEN I realized my flight is at 6AM.  Oops!  See you tomorrow. 

Search Challenge (3/11/15): Is the fruit getting sweeter?

It seems unlikely, but who knows? Maybe it's true.  

Today's Challenge comes to us from Regular Reader Miguel Viterbo.  Last week he wrote with an interesting question.  With his permission, I'm just going to quote his question as he sent it to me because it's a great example of the kinds of questions that we want to be able to answer.  (In fact, his writeup is much better than most.  Research questions are often vague and missing background and context--not here. This is an excellent Challenge statement.)  

My friends, family, and myself, have been noticing that in the most recent years (latest two to four years), fruits in Lisbon, Portugal are much sweeter than they were, especially in supermarkets and big superstores, where fruit was always worse than the one we could buy at local stores. 

Oranges and citrus fruits have been particularly noticeable in their increased sweetness.

We have no idea if this is a global trend, or if it's just true in Portugal.
At first, we tended to assume that supermarkets just got better at dealing with producers and acquired better stuff. In fact, most people I know didn't buy their fruit in supermarkets, so it's reasonable to expect that they had to fix that problem.

In the past months, though, we've heard rumors that farmers nowadays use sugar (or some kind of sweetener) added to the irrigation. Yesterday, the fruit shop owner in my neighborhood (whom I assume to be knowledgeable, because she has been picking her suppliers for 20+ years, and at a time was married to a producer herself, if I remember it right) told me that this was common knowledge (she said, "some time ago those sweeteners were added to the fertilizers, now they're within the irrigation itself").

(1) Is this true? Does this actually work to make fruit sweeter? 

(2) Should I be concerned?  Sugar is already hiding in so many everyday "non-sugar" foods (way more in the US than in Portugal, granted) that I don't want to take any more added sugar.  If it's really more sugar, how much more is it?  

I haven't spent any time trying to research this Challenge.  I didn't want to get a head start on this.  I want to check this out this along with all of you loyal Search Researchers.  

I have no idea if this is true, or if we're going to be chasing down an urban legend.  

That's why this is an especially interesting question:  We don't know how it's going to turn out!  

Let's begin on Miguel's Challenge.  What can you find out about this?  Is it true that farmer's are now adding sweeteners to their irrigation water?  

Unleash the hounds of Search Research!  Go!  

Let us know what you find out AND tell us how you did it. 

Search on.  



- Muito obrigado to Miguel Viterbo for this excellent Challenge.  

Answer: Finding and getting to know an obscure island

This was fun, eh? 


I'm glad you also enjoy learning about obscure places on the planet, and picking up a few lessons about how to search for information along the way.  

Finding this island was interesting.  But let's revisit our questions...  

1.  Can you find the island?  What's its name, and where exactly is it?  Is it an independent country, or is it part of another country?  

2.  The history of this island is fascinating--at the crossroads of history, but often not really a part of it.  Recently a cave was discovered on this island that has some rather old graffiti. What kind of graffiti is it?  Can you find a picture of the inscriptions?   

3.  Why is there a military tank on the island?  Who would bring such a thing there? 

Finding the island wasn't that hard, but there were a few hiccups along the way.  

My first search was (like many of you): 

     [ cave graffiti Arabian sea island ] 


I chose these terms as they seemed as though they would appear on any description of the island.  Location is always an important term, but not knowing ahead of time anything else about it, I chose to include the terms "cave graffiti" as that seemed pretty unusual--at least unusual enough to let me find the island.  

Sure enough, the results quickly led me to the island of Socotra (after a few moments being diverted by reading about cave paintings recently found in Petra--but that's not an island, so I stopped reading that quickly).  

Then, a quick search for just the island's name: 

     [ Socotra ] 

leads to a wealth of information, with the Wikipedia article being the most prominent. 

Socotra is just off the coast of Yemen and Somalia, solidly in the western Arabian Sea, at 12°30′36″N 53°55′12″E, nearly due west of Goa, south of Oman.  

I first looked it on Google Maps: 

And then zoomed in to take a look in Satellite view: 

In this view, you can see it's a chain of 4 islands, with the largest, Socotra, being mostly undeveloped, and pretty arid.  

It has fascinating flora (the Dragon's Blood tree, and a traditional frankincense source), and is also home to some remarkable caves.  

To determine the government, I read the entry in the Wikipedia entry which says that Socotra is a governate of Yemen, but then also checked CIA.gov Worldbook site  (just:  [site:CIA.gov Socotra ]  to cross-check.  (They tend to be pretty up to date about governmental issues, and they agree.)  

Because I want to be careful about these things, I also checked the Arabic language version of the Wikipedia page (available by clicking on the Arabic language link on the left-hand-side of the Wikipedia page--it looks like this:  العربية

That source (which is not just a copy of the English Wikipedia article) agrees.  It's part of Yemen.  

Finally I tried one last thing, just for completeness. 

I know that this is such an interesting place that a magazine like National Geographic MUST have something about it.  So I tested this out by doing a quick site: search like this:  

     [  Socotra site:nationalgeographic.com  ]

Which leads to several marvelous articles on the National Geographic site.

And then, just because I was really interested in Socotra, I decide to do a related: search as well, using one of the best articles from National Geographic as my seed text.  

      [related:ngm.nationalgeographic.com/2012/06/socotra/white-text ]

Leads to lots of related things… Really a great way to browse around and find great content.  

Graffiti:  Finding pictures of the Socotran cave art wasn't hard, but I really wanted some good context AND an authoritative source.  

I had noticed that there was a reference to the book "Foreign Sailors on Socotra. The inscriptions and drawings from the cave Hoq" in the references on the Wikipedia article, so I had to search for it. 

A search for the book title: 

     [Foreign Sailors on Socotra. The inscriptions and drawings from the cave ]

Leads to Academic.edu article Socotra Island, which is a great resource for all things academic that have been written about Socotra.  

Reading through those results then led me to the article, Les vestiges antiques de la grotte de Hôq (Suqutra, Yémen).   In: Comptes rendus des séances de l'Académie des Inscriptions et Belles-Lettres, 146e année, N. 2, 2002. pp. 409-445

Which has the following images (and much more): 

Images from the Academic.edu article.  

This is a marvelous book, written by archaeologists who have spent considerable time in the Hoq cave on Socotra.  Even if you don't read French, this is well worth looking at.  

Note how the first image (Fig 10) looks much like an Indian script, not an Arabic one.  There are a large number of inscriptions, drawings and archaeological objects. The majority seem to have been left by sailors who visited the island between the 1st c. BC and the 6th c. AD. The majority of the texts are written in the Indian Brahmi script, but there are also inscriptions in South-Arabian, Ethiopian, Greek, Palmyrene, and Bactrian scripts.  

A Tank?  It's really easy to check if there's a tank there.  A simple image search works well: 

     [ Socotra tank ] 

And clicking through on a few of those tells the same story over and over... "geez... we were on Socotra, and look at this tank we found."  

Question is:  How and why is it there? 

One clue I picked up was in the Arabic language Wikipedia article on Socotra:  "...Socotra [was] in the Convenant of the Soviet naval base military..for battleships and Walosatil..working until the unification of Yemen in 1990."  ("Walosatil" is the "Soviet Navy" transliterated.)  

I assume this means that the former Soviet Union found Socotra to be strategically interesting, and so had some kind of deal with them.  That hint suggested I search for: 

     [ Soviet tank Socotra ] 

That worked.  It led to multiple documents, including several first hand reports by war machine fans, who verified that this is a T34/85 (a popular Soviet tank).  

Just to double check that as well, I decided to check on the US "paper of record" with the query: 

     [ site:nytimes.com Socotra Soviet ] 

By looking at a few of those articles, it's pretty clear that the Soviets had a military relationship with Socotra (although they now seem to have moved away, and few traces of their existance there remains to be seen in Google Earth). 

However, according to one article on Socotora.info, "Soviet military ships preferred rather to anchor off Yemeni Island Socotra’s coast than in the Berbera port [on the Somalia coast]....Socotra had neither a port nor a mooring..."  (It's worth noticing that Socotra.info is a web site run out of Moscow, according to its WHOIS information.)  

The future of Socotra is clearly going to be interesting...  

Search Lessons:  

1.  Check multiple sources. As you can see, Socotra is an "in-between" topic.  There are references to it scattered across multiple sites, in multiple languages.  As Luís mentioned in his comments, many of the best references are in Russian (they were there for quite a while, doing extensive scientific studies).  We have to learn to check multiple kinds of citations! 


2.  Think about checking sources that are on the general topic, but might not show up in the top 10 (or 20) of the SERP.  As you saw, my search in National Geographic reveals a host of related and really interesting articles.  Unfortunately, you have to know to look in order to find them.  Keep in mind that sometimes a well-known site might have to be searched separately.  

3.  Check different kinds of resources.  That's why I looked at Images and Books, as well as the usual web search results.  


______________________________


Postscript:  About that "at least one million years.." reference at the top of my Challenge. 

As Luís found out, the Wikipedia article mentions the Oldowan culture in the very beginning, without much fanfare.  But if you follow that link, "The Oldowan, sometimes spelled Olduwan, is the archaeological term used to refer to the earliest stone tool industry in prehistory. Oldowan tools were used during the Lower Paleolithic period, 2.6 million years ago up until 1.7 million years ago, by ancient hominids."  Apparently some Russian archaeologists have found Oldowan tools on Socotra, made from local stones.  So... it's  been occupied for quite some time...