Bacanga State Park, State park in São Luís, Brazil.

Bacanga State Park covers about 2,974 hectares on the right bank of the Bacanga River, just south of São Luís. It holds a remnant of Amazon rainforest whose springs feed the Batatã reservoir, plus tidal mangroves and Mata dos Cocais. The terrain is laterite soil on gently sloping tabuleiros, small hills and valleys, split into four sub-basins.

The park was established in 1980 to replace an earlier watershed protection area created in 1944. This change upgraded its legal status and expanded management of the natural area.

Inside the park stand the ruins of Sítio do Físico, about 1,600 square metres of tannery, furnaces, tanks and warehouses built between the late 18th and early 19th century by Antônio José da Silva Pereira, physician-general of the Captaincy of Maranhão. After his death in 1817 the works turned to making fireworks. Tiles of the Pombaline period were found there, and Iphan has listed the site.

The park is accessible during daylight hours with trails through different habitats, and visiting in early morning or late afternoon is more comfortable. Sturdy shoes and plenty of water are important since the terrain is wet in places and sun exposure can be strong.

Archaeological finds within the park reveal human settlements from thousands of years ago, with shell mounds showing how early people used coastal resources. These remains offer rare evidence of the region's oldest inhabitants.