Machu Picchu

The camera stands on the path along the upper agricultural terraces, at the point where the whole thing opens up below you - the plaza, the temples, the long blocks of houses stepping down the spine of the ridge, and Huayna Picchu standing up dark behind them. This is the view that every photograph of Machu Picchu is a crop of, and the panorama shows what those crops leave out: the ground drops away on both sides into a gorge so deep that the cloud sits below you and moves through it while you watch, and the mountains on the far side are as high again. Turn round and the terraces climb away behind, dry-stone risers with grass on every tread, up towards the ridge. The stonework at the tripod is close enough to see the moss in the joints.

Machu Picchu is a pre-Columbian city overlooking Peru's Urubamba Valley. Also known as The Lost City, it stayed hidden until the early 1900s - completely unknown to the Spaniards during their conquest, and not seen by the outside world until a Yale professor reached it in 1911.

The Incas were extraordinary masons. Their sites were so solidly built that not even a knife could slip between the stones, fastened by a method called ashlar in which the stones are cut so precisely they sit atop one another with no mortar at all.

The same skill runs through the whole site. More than a hundred flights of stairs were built across the mountain region, most of them carved from a single solid chunk of stone.