Laguna Galletué, Mountain lake in Guallelmapu, Chile

Laguna Galletué is a lake in the Andes of Chile's La Araucanía Region, at 1,350 m, surrounded by mountains on three sides. Its eastern outlet is one of the two sources of the Biobío River, the other being nearby Icalma Lake. The surrounding forest, in the Valdivian Temperate Rain Forest ecoregion, includes araucaria (pehuen), lenga, ñirre and coigüe.

The area around the lake has long been used by the Pehuenche, an indigenous Mapuche group who hunted and gathered across these highlands. Over time, travelers and researchers mapped the region and documented its connection to the Bío Bío River.

The roads leading to the lake are rough in sections, so a vehicle with good ground clearance makes the trip easier. The warmer months offer milder weather and better access, while winter can bring snow and make some routes harder to travel.

The lake's eastern outlet is one of the two sources of the Bío Bío River, the other being nearby Icalma Lake. Upstream lies the Quinquén Valley, where more than 120 Pehuenche families received title to the land in 2007 after a century of dispute.