, also known as The Imperial City
, is a municipality in the Southeast Region of Brazil, inside the Rio de Janeiro state located 68 kilometres (42 mi) northeast of the Rio de Janeiro city. According to the 2010 National Brazilian Census, Petrópolis municipality had 305,917 inhabitants that year, up from 286,537 inhabitants at the last 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. Petrópolis is considered the safest city in the state of Rio de Janeiro and the sixth safest city in Brazil, according to IPEA classification for medium and large cities.