Sitting on an Italian hilltop is this surreal fortress built by the mad inventor of electrohomeopathy.

An ossuary built in 1210 to collect bones from the Ospedale Maggiore of Milan.

Thousands of well-dressed mummies below a monastery.

The final resting place of the poets Shelley and Keats.

Stalactites and stalagmites in a beautifully lit cave.

At the crypt of St. Mary of Eulogies and the Dead you are left alone to ponder mortality among piles of skulls.

The middle finger of modernity.

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

Famed for its pie, this eatery has a hidden tunnel that allowed Catholics to secretly walk to church during the Reformation.

The Pope’s secret escape route.