A tropical sky island
The Itatiaia Massif, part of the Mantiqueira mountain range, holds a unique ecosystem found nowhere else in Brazil: high-altitude alpine grasslands, known locally as campos de altitude. This environment exists in a narrow band generally above 2,000 meters, different from the dense Atlantic Forest below. The tundra's highest point is the Pico das Agulhas Negras ("Black Needles Peak"), which reaches an elevation of 2,791 meters (9,157 feet). This peak is the highest in Rio de Janeiro state.
The geology of the massif is distinct, primarily composed of alkaline igneous rocks like nepheline syenite that were put in place during the Cretaceous period. These rocks form the dramatic, pointed peaks that give the park its name; "Itatiaia" is from the Tupi language for "stone with many points". The entire massif is an intrusive alkaline formation covering over 215 square kilometers. The current landscape is a remnant of the last glacial period. During the Pleistocene epoch, when global temperatures were much colder, this type of grassland vegetation was widespread across central Brazil. As the planet warmed and glaciers receded, the forest expanded, leaving this high-altitude zone isolated, a cool "sky island" in a tropical sea of trees.