On our first full day in Cancun, we took a tour to Chichen Itza. It was a long bus ride into the mainland where we were kept entertained with a documentary and Apocalypto later in the evening. We visited our first Cenote along the way, drove through some destitute villages, and had lunch at a hotel where dancers performed Folklorico primarily consisting of balancing things on their heads.
The park where Chichen Itza is located is rather large, filled with various ruins and multitudes of street vendors. The main ruin can no longer be surmounted. Last year a woman fell to her death after slipping on the steps. They are being cleaned and made more safe with the promise of being reopened in the future. All sorts of interesting mathematics were incorporated in the construction of the ruins allowing for various audio and visual effects. They are quite a wonder to behold.