Clive heads north from Lazio’s capital, Rome, to the dramatic valleys of Italy’s badlands, out of which rises the fairy-tale citadel of Civita di Bagnoregio - Lazio’s ghost town. Meeting one of the 20 remaining residents, Clive finds out what it’s like to be outnumbered by a million annual visitors, and he explores the ancient tunnels beneath the town to discover why it’s slowly crumbling to dust