Reserva Laguna Negra, Nature reserve in Tolhuin, Argentina

Reserva Laguna Negra is a 1,204-hectare provincial multiple-use reserve in Tierra del Fuego, northeast of Lago Fagnano. Its southern boundary is the lake, the western boundary is the Corazón de la Isla reserve, the eastern boundary is the municipality of Tolhuin, and the northern boundary is private land. The reserve is a forested area suitable for sustainable forestry use, with the dark Laguna Negra standing out within it.

The region was home to the Ona people who lived across Tierra del Fuego before European settlement. Later the area experienced forest logging before its ecosystems were protected from further development.

The reserve lies beside the comuna of Tolhuin, whose urban area was proposed for expansion into reserve land in 2010; that project failed after objections from InFueTur, Fundación Vida Silvestre, FARN and Fundación Humedales. The name Laguna Negra refers to the dark lagoon at the centre of the 1,204-hectare reserve, bordered by Lake Fagnano to the south.

Two access points allow visitors to reach the area, with one pedestrian route starting from Hain camping along the lakeshore. Warm weatherproof clothing is essential since conditions remain windy and cool even during warmer months.

The dark lagoon formed through seismic activity and remains separated from a larger lake by a gravel barrier. This geological formation creates two distinct water bodies within the reserve with different environmental conditions.