Was watching some of the update recap videos yesterday and when I saw a quick runthrough of the new de_boulder commmunity map I instantly recognized it as somewhere I had been! It's based on the Meteora Monestaries in Greece.
What an incredible job by the map designer. The feeling "inside" the map is perfect and it alone made me begin to recognize the map, but the work on the skybox is what really immerses you as if you were there.
I've wanted to visit CS map locations for a while. Like for example, it's still on my list to visit the real world version of the classic Inferno T spawn. Well, this is my first time recognizing a map as somewhere I've already been. Cool feeling.
Great looking map.