Answer: Where'd the river go? What's the logo?

I first noticed the river's end because it didn't make any sense to me...  

When I went on my run, I got to that point at the river's edge and noticed that it just sort of... stopped!  That's the part that didn't look right to me.  How can a big river like this just quit?   

Here's a closeup of that part.  River's just don't do this.  They fan out, or get narrower and smaller--but they don't just just squared off at one end.  At least they don't do that naturally.  Here's a closeup: 

So this is an engineered cutoff.  But why?

1.  What's the story here?  When was the dark green river cut off from the pale green river?  Can you figure out when this happened?  How about WHY it happened?  What was the city hoping to accomplish?  

Like SRS Regular Reader Arthur Weiss, I thought this was an old bit of engineering.  So I looked for old, archival maps to start--I was hoping to see the original course of the river.  And while I could find lots of OLD maps (like this one below from 1860), it was remarkably hard to find maps that showed the river just outside of the city.  Here's one from 1826 that shows a very different river (islands!).  

Map of Seville from 1860.  Wikimedia.

That's when I turned to the Wikipedia article about the Guadalquivir river. I read the article and, like Arthur, noticed the map showing the various construction projects on the river over the past century.  

Map by Álvaro C.E. From Wikipedia.  

Look at the very top of the map--the Tapón de San Jeronimo is that bit of geo-engineering that cut off the river at the north end.  But read this map carefully--you'll see there have been a number of significant re-routes of the river.  In particular note that the old canal, Antigua corte de Chapina, has been filled in.  That area, like the Tapón de San Jeronimo is now used for something else. 

And, again, like Arthur, searching for:
     [ Expo 92 Tapón de San Jeronimo ] 

led me to the Washington Post's 1992 article about the engineering projects in Seville, including the creation of the Tapón in 1987.  

I also found this great diagram that lays it all out for us (from a great article on all of the engineering work needed to create the Expo 92 grounds).   

Geo-engineering on the Gudalquiver River in Seville.  From the History of the Seville Fair site.

  

All of this work over the years has been to control the periodic and terribly damaging flooding, with subsequent changes to fix problems that each solution caused!  (Prediction: There will be more river-engineering in Seville over the next 100 years.)  If you're interested, another article goes into great detail about the various projects over the years.  This was not a simple task!  

The second Challenge was obscure, but actually easy to solve... 

2.  What is the story behind the NO8DO logo?  Why does it appear everywhere in Seville--from a tomb in the cathedral to lampposts downtown, on sewer covers, and even the tops of bollards?  

As you see, the "8" symbol isn't just a numeral 8.    But I was puzzled about what it was--sometimes it looks like an infinity symbol, sometimes it looks like a skein of yarn.  

Here's a beautiful version of the logo as it appears on Christopher Columbus's tomb in the Cathedral: 

Reverse image search works well here, but I initially did the obvious search for: 

     [ NO8DO ] 

and quickly learned that this is the city's logo.  

The story goes that this logo began with the 13th-century coat of arms awarded to Sevilla by King Alfonso X the Wise for the city's loyalty. 

He gave this odd mark in gratitude for Seville's support of his wartime efforts in his battles against his son, Sancho IV of Castile.  

Sancho IV wanted to usurp his father's throne during the Reconquest of Spain (an immensely long power struggle on the Iberian peninsula, of which this is just one part).    

As you can see, between the ´NO and ´DO´ is an 8-shaped bundle of wool (madeja in Spanish). 

When you put all three elements together it forms a kind of rebus. If you then read it quickly, it sounds like no-madeja-do which,  more correctly would be spelled out as 'no me ha dejado' which means  "it (the city) has not abandoned me."  

It's a small award for a dangerous task, but hey, it's royal recognition! 

Search Lessons: 

1.  Diagrams are great.  Be sure to read them as they often have clues that are useful in your quest.  Don't just gloss over them!  

2.  Google Translate rocks!  I read Spanish, but there were lots of vocabulary I'd never heard of in these texts.  (tapón, pasarela, etc.)  But with the autotranslate feature of Chrome turned on, I was able to navigate all of these pages fairly quickly. 

3.  The MOST OBVIOUS search queries sometimes work really well.  We now know that the symbol in the middle of the NO8DO logo is not an 8... doesn't matter.  So many people have written about the logo as though it were a number 8 that this search works well.  Remember that you're searching what other people have written about these things.  Go with what's right in front of you--go with what's obvious, and that will often turn out to be the right thing.  

Search on!