Chich'en Itza flourished during the early postclassic period (800 - 1200 AD). The site is fascinating because of the controversial architecture at the site. Two styles, the Puuc and Toltec, were used in the construction of the separate structures. The resemblance of the Toltec architecture with that of Tula has led in the belief that at some time merchant-warriors from that city in the north overran and installed their culture at Chich'en Itza. The reverse may also be true but seems less likely, due to the fact that Tula developed the style uniquely.

Two large sacred wells called cenotes flank the site, providing both sources of water and religous purposes. Among the numerous palaces and temples is the famous Caracol, said to be the most advanced astronomical observatory of the ancient americas.