Petrópolis is a city in Rio de Janeiro (state). It is also known as The Imperial City of Brazil. Nestled among the forested hills of the Serra dos Órgãos, in the valley of the Quitandinha and Piabanha rivers, Petrópolis is a popular summer holiday spot. Besides the climate and surroundings, the main attraction is the former Summer Palace of the Brazilian Emperors, which is now a museum, specializing in Imperial history and memorabilia.
Petrópolis is home to the National Laboratory for Scientific Computing (LNCC), a research unit of the Ministry of Science and Technology of the Brazilian Federal Government.