Brazo Tristeza (Sadness Arm) is a deep glacial fjord in the southwest sector of Lake Nahuel Huapi, surrounded by steep mountains and waterfalls. This part of the lake covers an extensive stretch between Cerro López and Cerro Capilla, discovering numerous waterfalls (especially during the thaw or after rain). The forest gradually forms the dense Selva Valdiviana (Valdivian Rainforest).