This ancient Roman prison is decorated with an upside-down cross not as blasphemy but as saintly tribute.

These gutted monastery ruins still stand proudly in the middle of the Italian countryside.

The naturally mummified body of a peasant girl saint.

Fortified medieval tower house with lovely roof garden.

Geometry and mystery come together in an epic show of octagonal masonry.

The Pope’s secret escape route.

This hill made entirely of ancient Roman jars was simply a garbage dump to the people of the time.

Installed in an act of one-upsmanship, the annual sundial in this church is also a symbolic victory for the Gregorian calendar.

More sculpture than building, this architecturally significant temple was built on the spot of Saint Peter's crucifixion.

"The prettiest love letters in the world" ... or so said Lord Byron.

Renaissance hospital featuring a rotating door into which unwanted babies were dropped.

This private skyway is filled with art and was expanded explicitly so that Hitler could appreciate a river.

Fountain where visitors can earn a license to be mad.

The engineering wonder and pleasure dome of a much-maligned emperor still holds undiscovered secrets.

Secret refuge and museum of the Duke of Florence.

Ancient snack bar of the Roman Empire re-opened.

A Nesting Doll of Churches.

Jesus' footprints and the first catacombs in the world.

The only "Egyptian" pyramid in Europe and the legendary tomb of Remus.

The yawning maw of this pagan visage is said to bite off the hands of liars.

Venice's island of the dead.

The final resting place of the poets Shelley and Keats.

Over 50 exquisite hand-painted Renaissance maps decorate a Medici storage room.

Pilgrimage site for star-crossed lovers.