The largest known wine barrel of the medieval era is visible from the street in Gubbio.

A medieval tower with a suspended iron cage used as an open-air jail for criminals who were exposed as a warning.

The seat of the Mantua bishop holds many secrets within its walls.

This sculpture of a rhinoceros suspended above a city square is meant to evoke the weight of the human condition.

A rare example of an octagonal Catholic church.

The tomb of the mythological founder of Padua is not hidden in some obscure crypt, but stands right in the middle of the city square.

This medieval castle was home to a known tyrant and features several hidden passages.

Psychoanalyst Carl Jung reported a paranormal experience after visiting this mosaic-lined Roman baptistry.

This 6th-century church has the largest and best-preserved collection of Byzantine mosaics outside Constantinople.

An incredible mosaic-lined monument said to have held the remains of an ancient Roman empress.

This bustling Italian plaza is built on the ruins of an ancient Roman amphitheater.

Fountain where visitors can earn a license to be mad.

A beautifully well-preserved ancient Roman villa.

A sudden, striking cluster of hills south of Padua has been attracting visitors for centuries.

The origins of a large, medieval castle are shrouded in mystery, but now it's a delightful garden.

All that is left of this medieval castle is two towers, both of which now display a visible tilt.

The 1940s structure houses what was once Europe's largest telescope.

The remains of 50,000 World War I soldiers rest under a towering arch overlooking the Alpine battlefields.

An abandoned cyanide mill is now a haunting magnet for graffiti and illegal parties.

The first project by the Bureau of Reclamation illustrates both the upsides and downsides of reclamation.

The sump of the landlocked Carson River is a haven for wildlife.

This colossal underground passage paved the way for large-scale drainage and access tunnels across the U.S., but it almost wasn’t built.

The original building of a mining school endowed by one of the barons of the Comstock Lode now houses a museum of earth science and mining history.

The museum is housed inside the historic 1863 Carson City Mint.