Chichén Itzá, El Caracol (the Observatory)

Chichen Itza ("at the mouth of the well of the Itza") was a large pre-Columbian city built by the Maya people of the Terminal Classic. The archaeological site is located in the municipality of Tinum, in the Mexican state of Yucatán.

Chichen Itza was a major focal point in the Northern Maya Lowlands from the Late Classic (c. AD 600–900) through the Terminal Classic (c. AD 800–900) and into the early portion of the Postclassic period (c. AD 900–1200). The site exhibits a multitude of architectural styles, reminiscent of styles seen in central Mexico and of the Puuc and Chenes styles of the Northern Maya lowlands. The presence of central Mexican styles was once thought to have been representative of direct migration or even conquest from central Mexico, but most contemporary interpretations view the presence of these non-Maya styles more as the result of cultural diffusion.

Chichen Itza was one of the largest Maya cities and it was likely to have been one of the mythical great cities, or Tollans, referred to in later Mesoamerican literature. The city may have had the most diverse population in the Maya world, a factor that could have contributed to the variety of architectural styles at the site.

El Caracol, the Observatory, is a unique structure at pre-Columbian Maya civilization site of Chichen Itza. El Caracol, which means 'snail' in Spanish, is so named due to the spiral staircase inside the tower.

The structure is dated to around AD906, the Late Classic period of Mesoamerican chronology, by the stele on the Upper Platform.

It is suggested that the El Caracol was an ancient Mayan observatory building and provided a way for the Mayan people to observe changes in the sky due to the flattened landscape of the Yucatán with no natural markers for this function around Chichen Itza. The observers could view the sky above the vegetation on the Yucatán Peninsula without any obstruction.