Ciudad Colonial (Spanish for "Colonial City") is the first settlement made by Christopher Columbus and the Spanish explorers in the New World. It has been declared a World Heritage Site by UNESCO. Colloquially known as "Zona Colonial" (Colonial Zone), Ciudad Colonial is part of the original Santo Domingo, Dominican Republic, and the origin of the district dates back to the 16th century. The District is located in the west corner of the Ozama River, which bisects the city. The district today covers less than 5 square kilometers.