Lagunas de Alto Perú

The ground is páramo and wet puna: dark moorland, peat, cushion plants and standing water, with the lagoons scattered across it rather than gathered in one place. It is the kind of country that holds water through the dry season and feeds the rivers below, which is the reason it matters beyond trekking and the reason it has become a focus for conservation and ecotourism efforts in the region.

This is a full day and a genuine high-altitude one. At 3,900 metres the city's 2,750 is no preparation; this is more than a thousand metres above where you have been sleeping, and it should come late in a trip rather than early. The days are warm and the nights cold year-round here, and the swing between midday and after dark is larger than most visitors expect, and layers matter more than a heavy coat. May to October is the window; the ground is boggy at the best of times and impassable in parts during the wet season.

A note on the limits of this entry: route access, whether a guide is required, and the current state of community ecotourism arrangements at Alto Perú all need checking locally. Do not set out for this one on the strength of a web page.