The document discusses three major civilizations of Central and South America: the Aztecs, Mayas, and Incas. It provides background information on their cultures, achievements, and ways of life. The Aztecs built the city of Tenochtitlan on Lake Texcoco and were known for human sacrifice. The Mayas had advanced knowledge of astronomy and built pyramid temples used as calendars. The Inca Empire stretched along the west coast of South America, and they constructed elaborate road systems and cities made of stone.