El Caracol, the Observatory, was dedicated to the study of the movement of the stars and planets and is one of the most beautiful accomplishments of the Maya in Yucatán.

The Observatory which consists of a tower built on two rectangular platforms, was built during different periods. The tower itself is more recent than the platforms. Inside the tower there are a number of small windows which were used to study the movements of the stars as well as an unusual stairway, resembling a snail shell, which leads to the highest part of the tower for closer observations .

The Maya's deep interest in astronomy and calendars helped the Mayas to establish the cycle for sowing crops and other activities which were important to the economic and social life of the city.

The tower is about 13 meters in height and the observatory measures 22.5 meters high. Above the doorways in the observation tower there are carvings of the rain god, Chaac to whom some believe the building may have been dedicated.

[Based on Let's Learn about Chichén-Itzá , Chichén-Itzá: The City of the Wise Men of the Water. by Roman Chan, All About the Mayas. by C. Dorese. published by Producción Editorial Dante (Mérida, Mexico) and Incidents of Travel in the Yucatan by Stephens and Catherwood published by Smithsonian Institute Press (Washington D.C.). All available in paperback and highly recommended.]