Costa do Sol State Park, State park in Rio de Janeiro state, Brazil.

Costa do Sol State Park is a mosaic of 27 discontinuous protected areas across six municipalities of Rio de Janeiro state, including parts of the Atlantic Ocean and the Araruama Lagoon. It covers about 9,840.90 hectares of Atlantic Forest remnants, restingas, mangroves, lagoons and swamps, with more than half its area inside the Massambaba Environmental Protection Area.

The park was created by state decree 42.929 on 18 April 2011, with about 9,841 hectares, at a ceremony in Búzios attended by environment minister Carlos Minc and governor Sérgio Cabral Filho. The proposal came from the Lagos São João Intermunicipal Consortium (CILSJ), a working group of municipalities, companies and civil society. It was Brazil's first mosaic park, made of discontinuous protected areas.

The park holds ancient sambaqui archaeological sites that reveal evidence of prehistoric communities living along this coast thousands of years ago. Today you can still see traces of these old settlements scattered throughout the land, showing how people once lived here.

The park is a mosaic of 27 discontinuous areas across six municipalities, so plan which sector to visit in advance. As of 2015 there was no visitor center or lodging for rangers, and little had been done to manage tourist use sustainably. The park's rangers have fought 25 fires since 2011, so check local conditions before setting out.

Lagoa Vermelha contains unusual limestone formations created by microorganisms that reveal rare geological processes. These formations offer glimpses into natural processes that unfold across long stretches of time.