Nahuel Huapi is a deep glacial lake that spreads 529 square kilometres of dark sapphire water into seven long arms reaching between the peaks of the northern Patagonian Andes. It drops some 460 metres, among the deepest lakes on the continent, and forested islets are scattered across its surface. The shores carry cinnamon-barked arrayán myrtles and southern beech, and the spires of Cerro Catedral and the glacier-capped summit of Tronador close the horizon. Ice-age glaciers ground these valleys out along old fault lines, then dammed them with rubble as they retreated, leaving the water at 770 metres. The town on its shore, Bariloche, is the base for all of it.
The classic view is from the top of Cerro Campanario, a hill on the lake shore with a chairlift to the summit. In autumn, through April and May, the beech forests burn crimson and amber against the cold blue water; in winter the same slopes turn white and Cerro Catedral becomes one of South America's largest ski resorts. At the northern end of the lake, reached only by boat, the Quetrihué peninsula holds a stand of arrayán grown to full tree size. The myrtle's cinnamon bark is cold to the touch and peels away in thin sheets. Catamarans cross to it from Puerto Pañuelo below Llao Llao, calling at Isla Victoria, the largest island on the water. Bariloche itself wears Swiss-style chalets and chocolate shops, and the park behind it now guards more than 7,000 square kilometres. The lake is only its front edge: the ski mountain, the granite spires above Refugio Frey and the ice of Tronador are separate days from the same town.