High on a dusty hill outside Lima, a sign rippled in the wind: “Zona Intangible,” it said. In-tan-gi-blé, in Spanish, but the literal meaning is the same: untouchable. The Untouchable Zone. For a minute, I thought it might mean there were dangerous chemicals buried there, or live electrical wires, or something else it would be very dangerous to touch. But no: what the sign meant was: don’t try to build your house here. Just a few hundred yards downhill, we watched a few family groups hacking level spaces in the soft sand. One family had some pre-nailed walls stacked nearby: their future one-room home, at the ready.  Another young couple let their two-year-old son take a turn with the shovel. This is the uphill edge of Manchay, a sprawling community of about 100,000 people on the outskirts of Lima. It is one of many asentamientos humanos, human settlements, that have sprung up around Peru’s capital city, where one out of every three of the country’s 30 million people now live. On a first visit to Manchay, it is very hard to imagine why anyone would want to live in this place. Most of the roads are unpaved, churning up constant clouds of dust, which coats everything, including the occasional brave flower garden or struggling tree. And yet: there is another kind of Zona Intangible here. Manchay was founded by people whose driving desire was to live in peace. Most of them came from a landscape that could not have been more different from this one: the [...]