Here, 100ft down and hidden from public view, lies an astonishing secret - one that has drawn comparisons with the fabled city of Atlantis and has been dubbed 'the Eighth Wonder of the World' by the Italian government.
For weaving their way underneath the hillside are nine ornate temples, on five levels, whose scale and opulence take the breath away.
Constructed like a three-dimensional book, narrating the history of humanity, they are linked by hundreds of metres of richly decorated tunnels and occupy almost 300,000 cubic feet - Big Ben is 15,000 cubic feet. ...
But the 'Temples of Damanhur' are not the great legacy of some long-lost civilisation, they are the work of a 57-year-old former insurance broker from northern Italy who, inspired by a childhood vision, began digging into the rock.
It all began in the early Sixties when Oberto Airaudi was aged ten. From an early age, he claims to have experienced visions of what he believed to be a past life, in which there were amazing temples.
Around these he dreamed there lived a highly evolved community who enjoyed an idyllic existence in which all the people worked for the common good.
Obviously nuts, but extremely cool to see. I'd love to go visit.