Petrópolis is a municipality located in the interior of the state of Rio de Janeiro, Brazil, also known as Imperial City. It occupies an area of 795,798 km ², counting on a population of 305 917 inhabitants (2014), according to IBGE. Besides being the largest and most populous city in the Serrana Fluminense region, it also has the largest GDP and HDI in the region. The Petropolitans belong linguistically and culturally to the Cariocas family, a group to which more than 70% of the population of the modern State of Rio de Janeiro belongs.
Petrópolis is the safest city of the state of Rio de Janeiro and the sixth safest city of Brazil, according to classification of IPEA for cities of medium and big sizes. Petrópolis is the headquarters of the National Laboratory of Scientific Computation,  a research unit of the Ministry of Science, Technology and Innovation.
The mild climate, the historic buildings and the abundant vegetation are great tourist attractions. In addition, the city has a busy commerce and services, besides agricultural production (with emphasis on fruit growing) and industry. Founded on the initiative of the Emperor Dom Pedro II (his name comes from the junction of the Latin word Petrus (Peter) with the Greek in Pólis (city), being "City of Peter"). It is often called the "Imperial City" because it is Dom Pedro's preferred route to his leisure and rest. It was state capital temporarily between 1894 and 1902, due to the Armada Revolt.