When the Spanish conquered Tenochtitlan in 1521, they destroyed most of the old Aztec public buildings but kept the basic layout of the city, which roughly extends over what is now known as the historic center or Colonia Centro. The Cathedral was built over a portion of the sacred precinct (teocalli) of the destroyed Templo Mayor, the National Palace was built over Moctezuma's New Palace and the Zocalo was built over what was an open space near the sacred temple space. Over the early colonial period, European-style construction would replace Aztec ones over the entire island city, with the most important public buildings concentrated on the blocks adjoining the Zocalo.