Mount Roraima is the giant of the Pacaraima tepuis, a 31-square-kilometre sandstone plateau standing at 2,810 metres where Venezuela, Brazil, and Guyana meet. The summit is permanently in cloud for most of the year, and from below the cliffs appear and disappear behind shifting white walls. The rock is some of the oldest exposed material on Earth — close to two billion years.
The standard trek leaves from the Pemón village of Paraitepui and takes five to six days return. You camp on the savanna the first night, climb the "ramp" — the single non-vertical route up — on day two, spend a day or two exploring the summit, and reverse the route. Pemón guides are mandatory by law. Conditions on top are otherworldly: black quartzite pavements, crystal valleys, rock formations weathered into spires and hollows, and endemic plants found nowhere else.