CHICHÉN ITZÁ: The so called "Caracol" which is considered to have served as an astronomic observatory is one of the most important buildings in the Maya-Toltec ruins of Chitchen Itza. It dates from the transitional time after the fall of the Maya culture, that is to say from the end of the first millenia, and already has Toltec influence.
Hints: Avoid Sundays, when admission is free for locals. Try to sleep nearby and go early before the arrival of the busses from Cancún.
Note: This image was scanned from a slide with Hamrick Vuescan on a Reflecta Crystalscan 7200 (Primefilm PF 7250 U).