The Maya Indians of Central America and Mexico developed one of the most advanced early cultures. The Maya civilization reached its peak during what is called the Classic Period, from about A.D. 250 to 900. During this period, the Maya built large cities that included palaces, pyramids, temples, and terraces. The ruins of many of these structures still stand.<NP> The Maya studied astronomy, invented an accurate yearly calendar, and developed an advanced form of writing. They also produced magnificent painting, pottery, and sculpture. In addition, the Maya built a vast system of underground canals to irrigate their fields of corn, beans, and squash.<NP> For reasons still unknown, Maya civilization began to decline during the 900's. Many Maya sites were abandoned. Today, descendants of the Maya live in the mountains of Mexico and Central America. Many of them still speak Maya languages.
