Of course you could go on a real walk near Barcelona with kaleboel:
http://oreneta.com/baldie/blog/
(click on walks)
Sounds exhausting, though.

We also have the famous Rambles in Central Park here in NYC, once a notorious wilderness of muggery and buggery (if I may say so). Of course, the origin of the English cognate of rambla (Del ár. hisp. rámla, y este del ár. clás. ramlah, arenal) is a bit different:

c.1443, perhaps frequentative of romen "to walk, go" (see roam), perhaps via romblen (c.1378) "to ramble."

Or

Probably from Middle Dutch *rammelen, to wander about in a state of sexual desire, from rammen, to copulate with.

The latter probably explains the Gotham usage, juding from our Dutch history and what goes on there.

The Spanish etymology goes back to Covarrubias, the 17th century lexicographic pioneer and legend.

I don't have anything smart to say about it except that in parts of Spain a rambla is a treelined avenue (for strolling, I guess). I am not sure why Spanish would add the 'b' -- why not a Germanic source? but I will leave that to the historical linguistic freaks. Ramlah means a tract of sand or, most commonly, a dune in Classical Ar. Oh well. I'm rambling, sorry. I was born a ramblin' man.

In most cases the water's still there, piped underground (bit like London's lost rivers). There are still a couple of villages down the coast that haven't been modernised, and every spring someone's Seat gets washed away.