Lake, central Mexico.
Originally one of the five lakes of the Valley of Mexico, Texcoco has been drained by channels and a tunnel to the Pánuco River since the early 17th century. It now occupies only a small area surrounded by salt marshes just east of Mexico City . Tenochtitlán , the Aztec capital, stood on islands in old Lake Texcoco and was connected to the mainland by causeways.