Thanks for the warm welcome everyone! I'm very happy that my country finally got to host a leg of the Race.
That tile was very popular for a while here.
Besides the diagonal tiles, the Twitpic also shows a very small space, with a wall on at least one side of it and Plaza de la Independencia is a very open space. The wall shown in the pic has a fence above it.
Since there seems to be some people not related to the show, including the person who took the photo, I imagine it's a public square and Escalinata Antequera is the only walled square I know of in the area that was actually built in a small hill. And, as shown in
the picture I linked to in my 2nd post (sorry I don't know how to show you the Panoramio photo directly), the walls surrounding the Escalinata have fences above them.