From the air, you see it only through the constant jolt, tilt and shudder of the low-flying Cessna aircraft. The landscape of the Llanos de Moxos, northern Bolivia, appears as a disconnected patchwork of open grassland savannahs, forest islands and lakes. It feels random, almost unreadable. Only gradually does the pattern resolve itself: raised causeways or paths fanning out to link the forest islands, and a dense, scattered web of canals threading the terrain. Slowly you realise it’s a structured network of intersecting lines, enclosures and roads – the imprint of past human design. Aerial view of Llanos de Moxos. Jose Iriarte, CC BY-SA If you stand on the open savannah, there is almost nothing to see of this ancient network. The horizon feels open, with fires in the distance from local people burning pastures and clearing forest as dry season begins. The old geometry is still faintly perceptible, but you have to know how to look. Step into the patches of forest and the canopy closes in. The earth softens underfoot and mosquitoes descend …