On a green hillside outside Rome, something strange is happening. Cracks in the ground begin to emit steam, and animals drop dead owing to asphyxiation. Deep beneath the ground, meanwhile, an earthquake starts to rumble. Is this great city doomed, then, to a terrible fate?
Some 12 miles southeast of Rome, a semicircular formation of hills stretches for nine miles across the Italian landscape. Known as the Alban Hills – or Colli Albani – they have been the site of human settlements all the way back to prehistoric times.