São Cristóvão (Portuguese pronunciation: [sɐ̃w kɾisˈtɔvɐ̃w], Saint Christopher) is a Brazilian municipality in the Northeastern state of Sergipe. Founded at the mouth of the Vaza-Barris River on January 1, 1590, the municipality is the fourth oldest settlement in Brazil. São Cristóvão is noted for its historic city square, São Francisco Square, and numerous early colonial-period buildings. The 3 hectares (7.4 acres) site was designated a UNESCO World Heritage Site in 2010.São Cristóvão covers 437 square kilometres (169 sq mi), making it the third largest settlement in the state of Sergipe behind Aracaju and Nossa Senhora do Socorro. Its population is 91,093 (est. 2020) and has a population density of 196.43 per km2 (508.8/sq mi). São Cristóvão is home to the Federal University of Sergipe, which was established in 1968.