Hey, @dswigle.

Chichen Itza is one of my favorite places to visit. Went down with a friend from work the first time and then again with my wife several years later. Both very incredible experiences. The acoustics at the ball court is simply amazing. We weren't with a tour, but one of the guides demonstrated the echoes (I believe seven) that literally bounced off different points of the walls. The most incredible thing, though, was when my friend went to one end of the ball court and me on the other and I could hear him speaking normally as if I were right next to him. That' s a distance of 168 meters or 551 feet! Totally freaky!

It's too bad that they haven't allowed climbing the pyramid for sometime. I understand they mimic the solstices at night with some kind of light show so tourists don't have to wait. Not exactly the same, I'm sure, but plays to the amazing feat of architecture.

Chichen Itza, along with other prominent ruins, is indeed still a market place, since there are a lot of vendors wondering around, trying to hawk their wares. My wife liked bartering with them. I was more interested in the ruins. :)

Crawling into one of the saunas was cool. I liked The Observatory, and the whole idea of the knowledge they had about astronomy in general, and Cenote Sagrado was pretty incredible until we were told it was used for human sacrificing, although I guess that could be up to some debate.

I'd very much recommend Chichen Itza to anyone. I'd add Teotihuacan outside of Mexico City as a must see, too, just because of the pure scale of everything there. Enormous! As far as intact buildings and architecture goes, though, Chichen Itza is hard to beat.