Petrópolis, also known as The Imperial City, is a municipality in the Southeast Region of Brazil. It is located in the state of Rio de Janeiro, 68 km northeast of the city of Rio de Janeiro. According to the 2010 National Brazilian Census, Petrópolis municipality had 295,917 inhabitants that year, an increase from the 286,537 inhabitants at the previous census. Besides being the largest and most populous city in the Fluminense Mountain Region, the city also has the largest GDP and HDI in the region.