The document provides information about three ancient Mesoamerican civilizations: the Maya, Aztec, and Inca. It discusses their locations, political structures, religions, accomplishments, and eventual declines. The Maya settled in what is now the Yucatan peninsula and had numerous independent city-states. They developed advanced calendars, mathematics, and hieroglyphic writing. Around 900 AD, many Maya abandoned their cities due to a severe drought. The Aztecs built the great city of Tenochtitlan in present-day Mexico and created an empire through conquest and tribute. They practiced human sacrifice on a large scale before being conquered by the Spanish in 1521. The Inca ruled a large empire from Cuzco