Neighboring states are (from west clockwise) Rondônia, Amazonas, Pará, Tocantins, Goiás and Mato Grosso do Sul. It also borders Bolivia to the southwest. A state with a flat landscape, alternating great chapadas and plain areas, Mato Grosso presents three different ecosystems: Cerrado, Pantanal and the Amazon Rainforest. The vegetation of the open pasture covers 40% of the state, and the Chapada dos Guimarães National Park, with its caves, grottos, tracks and waterfalls, is one of its great tourist attractions. In the north is the Amazonian forest, with a biodiversity covering half of the state. The Xingu National Park and the Araguaia River are in Mato Grosso. Further south, the Pantanal, the world's largest wetland, is the habitat for almost a thousand species of animals, with many aquatic birds.
In 1977, the state was split into two halves, with Mato Grosso do Sul becoming a new state. The Bororo Indians live in the Mato Grosso area. As late as 1880, soldiers patrolled lands on the outskirts of Cuiabá, Mato Grosso's capital and largest city, to protect settlers from Bororo raids.
By the end of the 19th century, although severely reduced by disease and by warfare with explorers, slave traders, prospectors, settlers, and other indigenous groups, as many as five to ten thousand Bororo continued to occupy central and eastern Mato Grosso, as well as western Goiás. The southwestern part of it was ceded to Bolivia in exchange for Acre, according to Treaty of Petrópolis in 1903.
The historic remoteness of this area led it to be the subject of exploration, most notably by Captain Percy Fawcett, in the quest for lost cities. It was also the rumored location of access to the interior of the earth in various Hollow Earth theories.