“Show me a better window.” A friend had laid down the challenge on Instagram with a golden view of a Tuscan cornfield.

Here was one that trumped hers. It gathered into its plate-glass rectangle a steel-blue immensity stretching almost to the horizon, inviting you to lose yourself in the interplay of light and shadow on the canvas of the water. Clumps of violet-grey storm clouds roiled slowly across the horizon; slanting streaks of rain were lit up as if by a spotlight from the wings.

Titicaca: if once it catches your imagination, it never lets go. As a child I laughed at the lake’s comedy name, and fantasised about the legends of ancient cities and Inca treasures sunk in its depths. Poring over the atlas in my fourth-form geography class, I was awed by the notion of a navigable lake almost 300 metres deep, cradled in a mountain plateau nearly three times higher than the UK’s highest peak.