Close to but not part of Parque Nacional Nevado de Tres Cruces, by the border with Argentina, the stunning, blue-green Laguna Verde lies at the foot of the highest active volcano in the world, the 6893m Volcán Ojos del Salado. The first, sudden sight of Laguna Verde is stupendous. The intense colour of its waters – green or turquoise, depending on the time of day – almost leaps out at you from the muted browns and ochres of the surrounding landscape. The lake lies at an altitude of 4500m, about 250km from Copiapó on the international road to Argentina (follow the signs to Paso San Francisco or Tinogasta). At the western end of the lake, a small shack contains a fabulous hot-spring bath, where you can soak and take blissful refuge from the biting wind outdoors. The best place to camp is just outside the bath, where a stone wall offers some protection from the wind, and hot streams provide useful washing-up water. At the lake’s eastern end there’s a carabineros checkpoint, where you should make yourself known if you plan to camp.