Civita di Bagnoregio Geography & Climate

The geology here is unusually easy to read because it is doing something visible. A cap of hard volcanic tufa sits on a thick bed of soft marine clay. Rain works into the clay, the clay slumps, and the tufa above it loses support and breaks away in blocks.

The result is the calanchi — steep, bare, deeply gullied badlands running down either side of the ridge. They are spectacular and they are the mechanism of the town’s destruction.

Civita was once joined to Bagnoregio by a saddle of land carrying a road. That saddle has gone. Two rivers, the Torbido and the Chiaro, cut the valleys on either side, and the two settlements now face each other across an open gap.

The wider area is the same volcanic country as the rest of the Tuscia, with Lake Bolsena — a crater lake, the largest in Europe — about fifteen kilometres west.

Civita has the inland Mediterranean climate of the Tuscia: hot dry summers, frequently in the low thirties Celsius, and cool wet winters generally between two and twelve degrees, with frost and occasional snow.

The town sits on an exposed outcrop with no shelter in any direction, which makes it windier and colder in winter than the surrounding valley and hotter on the bridge in summer — the crossing is three hundred metres with no shade at all.

Rainfall is the variable that matters beyond comfort. Heavy or prolonged rain drives the landslips, and the bridge and town can close in severe weather. Autumn and early spring are the wettest periods.