Mexico City, one of the largest metropolitan areas in the world, sprawls across the Valley of Mexico. Originally the Aztec city of Tenochtitlan, the city was constructed over the ancient Lake Texcoco. The arrival of the Spanish saw the demolishment of most structures. However, some centuries-old canals and ruins can still be found. Head to the historic centre to see a host of architectural and cultural attractions, including the Plaza de la Constitucion, the National Palace, the Metropolitan Cathedral, the Templo Mayor, the Palace of Fine Arts and the scenic Central Alameda Park. Top attractions such as Chapultepec Castle, the Modern Art Museum and the National Museum of Anthropology can be found in Chapultepec Park.