A vast lake at 3,812 metres above sea level on the Andean altiplano, where the Uros people have built their homes on floating islands of woven totora reeds for centuries.
At 3,812 metres above sea level, Lake Titicaca is as high as the cruising altitude of many light aircraft. The air contains 40% less oxygen than at sea level. Newcomers move slowly, breathe deliberately, and feel the altitude as a physical weight. The Aymara and Quechua people who have lived here for thousands of years no longer notice it — their blood carries more red cells, their lungs are larger, their hearts pump more slowly and efficiently. They evolved to live here.
The lake itself is vast — 8,372 square kilometres, the surface area of Puerto Rico — and extraordinarily deep, reaching 281 metres in its deepest sections. It is so large that it creates its own regional microclimate, moderating temperatures on the high plateau that would otherwise be too cold for agriculture. The Inca regarded it as the birthplace of the sun, the place from which Viracocha emerged to create humanity. A temple island in its centre — Isla del Sol — marks the spot.
The Uros people have lived on the lake''s surface rather than its shores for centuries, constructing floating islands from totora reeds — a buoyant aquatic plant that grows in the shallows. The islands must be constantly maintained: the base reeds rot from below as new reeds are added on top. The process is never finished. Some islands have been inhabited continuously for hundreds of years, gradually replacing themselves from the bottom up.
From the lake surface, the Andes rise on all sides. The sky is very close, the blue very dark, the light intense and thin.