The lake that gives Bariloche its setting is a glacial trench 100 kilometres long, with a maximum depth of 460 metres, and a coastline so indented that it adds up to over 350 kilometres. It is the centrepiece of Nahuel Huapi National Park, Argentina's first, established in 1934 after Francisco Moreno donated land for its creation.
The waters are an extraordinary deep blue, fringed with forests of coihue and cypress and ringed by snow-capped Andean peaks. Boats leave from the Puerto Pañuelo pier for the standard day trip to Isla Victoria and the Arrayanes forest. Smaller catamarans ply the shorter routes around the bays. Swimming is possible in summer for the brave — the surface barely reaches 18 °C.