Barcelona's busy main street. There's a large island that runs down the middle of it from the Plaça Catalunya to Columbus Monument. On this island you can see many street performers, artists, musicians, newsagents, flower stalls, people trying to sell tourist junk to you, and a metro station or two. The street is quite old and picturesque, and generally quite busy. There is lots of nice architecture to see, and a few monuments too. Don't make the mistake of stopping for food or drink on the terraces on La Rambla, they overcharge quite a lot in my opinion.

(Thanks Girlface and Koala).
La Rambla refers to "the torrents" which would
to be completed.