There used to be a river running through Valencia. It was called the Turia and in 1957 it flooded the city causing massive damage. As a result, the river was diverted away from the city and the old riverbed was planted over with grass, trees and other natural growing stuff (this is boring, historical stuff, but it‘s good to know and, I think, counts as a genuine Euro-fact). Today it’s a huge sunken park running pretty much the length of the city. You can walk it, as I did, and what a wonderful walk it was.