Wadi Qelt is a desert gorge running down from the hills of Jerusalem to Jericho, and the footpath through it is an aqueduct two thousand years old. The two things go together better than they sound. An aqueduct only works if it falls at a steady, gentle gradient, so the channel never climbs and never drops away under you. It contours the gorge wall from one spring to the next, with shallow clear water beside your boots, until the monastery comes round a bend on the cliff opposite. One of the springs does not behave. Ein Fawwar, halfway up the wadi, gushes, stops, runs dry and then gushes again. Water fills a hidden cavity until it spills over a natural siphon and empties in a rush; air breaks the flow, and the cavity starts filling again.
Behind the monastery's blue domes are cool stone rooms built straight into a natural cave. A small Greek Orthodox community still lives in them, and the church keeps the relics of three saints of this wadi. Below it you can leave the channel and scramble down to the canyon bed, where the walls close in and the domes hang over you. The bed is dry stone most of the year, because the water is all up in the channel; rock hyrax bask on the ledges and gazelle keep to the ridgelines. Rain on the Jerusalem hills changes that within hours, and brown floodwater comes down the gorge under a clear sky. The old road between Jerusalem and Jericho ran along the ridge just south of here, and it was robbed often enough that the Good Samaritan was set on it. In spring and autumn buzzards, kites and snake eagles ride the thermals along the cliffs. The rock face above the monastery is pitted with dark openings. Some are plain caves, some are walled-up shelters on ledges with no visible way up to them. They are not all ancient: a Romanian hermit called John Jacob moved into one in 1953 and lived there until his death in 1960, and his body lies in the monastery below.