ANAHUAC

historical and geographic region of Mexico. The heartland of Aztec Mexico, Anhuac (Nahuatl: Land by the Water) designated that part of New Spain that became independent Mexico in 1821. The original Anhuac of the Aztecs was the central plateau valley of Mexico, an area about 50 miles (80 km) long by 30 miles wide, with an average elevation of 7,500 feet (2,300 m). When the Spaniards arrived in 1519, the valley contained five interlocking lakes (Zumpango, Xaltocan, Texcoco, Xochimilco, and Chalco), in the midst of which stood Tenochtitln (now Mexico City), the Aztec capital, linked to the mainland by three long causeways. In 160708 much of the water was drained off to the Pnuco River system by a ditch and tunnel, and in the 20th century Lake Texcoco was further emptied. Its salt marshes remain, as do Xochimilco's floating gardens, but the vast water area is gone. Saline deposits make the reclaimed land unfit for agriculture, and the lake beds give Mexico City a very unstable subsoil.