Altevatnet (Northern Sami: Álddesjávri) is Norway’s 11th largest lake at 79.71 square kilometres (30.78 sq mi). The lake is approximately 38 kilometres (24 mi) long and about 2.5 kilometres (1.6 mi) wide. It is located in the municipality of Bardu in Troms county. It is also the largest lake in Troms county. The lake is regulated by a dam on the northwestern end of the lake.