The Laguna Brava is a deep blue lake 17km by 10km, whose high potassium-chloride levels make it undrinkable. When it’s blowing a gale, huge waves can be whipped up; when there is no wind, the mirror-like waters reflect the mountains behind. Behind stretches a panorama of 6000m peaks, including the enormous Pissis – the second-highest volcano in the world (6793m). Other lakes in the reserve are the smaller Laguna Verde – a green lake as its name suggests – and the Laguna Mulas Muertas, often covered with pink flamingoes, Andean geese and other wildfowl. There’s no public transport, no guardería and nowhere to stay: just you and the wilds.