So after we spent a long time up on the Acropolis this old guy comes up to us, the same guy who greeted us informally while we were searching the hacienda, and explains that there's a "gruta" (cave) some distance away. He encourages us to walk over there, and tells us to be careful. We walk through high brush on a maintained trail and we're not sure what we'll see until we find this half buried cave, part of the ancient Mayan structure. This was the first cave we saw incorporated into a pyramid-like structure and it started us thinking about the possibility that all of these sites might have been built around water sources.