A spectacular crater lake inside the Cotacachi-Cayapas Ecological Reserve, about 18 km west of Otavalo near the town of Cotacachi. Two small volcanic islands rise from the deep blue water, and the rim trail circles the entire caldera in three to four hours with sweeping views over the Andes. The lake sits at 3,070 metres, so the walk has a brisk feel even in the dry season. Boat tours run from the dock at the visitor centre if you prefer the view from the water. The name means "guinea pig lake" in Kichwa — a reference to the shape of the two islands.