A horde of stray cats rule in this secluded Parisian cemetery under a bridge.

The oldest stone house in Paris was built by its most famous alchemist.

This massive library holds what was once the largest book collection in the world.

Abandoned railway line circling the city of Paris.

France's most famous cemetery, with some of its most curious tombs.

High in the Italian Alps, a lonely chapel with a striking view of the Matterhorn.

A British Commonwealth cemetery in the heart of Milan, with 421 allied soldiers died during World War II.

This beautiful Romanesque church preserves stunning medieval frescoes and the excavations of a Roman market town.

This building was designed to celebrate Italy's victory in World War I.

Three underground crypts and a pointed arch under the bell tower make this cathedral unique among Romanesque churches.

A floating bridge leaning on barges allows pedestrians to reach the historical center.

An impressive bridge over a ravine also served as an aqueduct.

Two of the few remaining life-sized Greek bronzes were submerged in the sea for over 2,000 years.

This Roman monument is surrounded by more recent construction, offering a stark contrast between ancient architecture and the modern urban landscape.

This Roman theater was crafted into the local tuff rock and was rediscovered during the 19th-century.

Constructed during the 1960s, this bridge is still the highest in Italy.

Although their purpose is unknown, these ancient Roman supporting arches showcase Hellenistic ingenuity.

A crumbling watchtower and a lighthouse overlooks the site believed to be the Sirens' cliff in the "Odyssey."

This high-speed test track is popular with car manufacturers, speed freaks and orbiting astronauts.

A fairy-tale-like forest that was sacred to Jupiter and Saint Anthony.

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

These pillars at the main entrance of this church are actually a hidden musical instrument.

Something's missing between the arcades of the Palazzo della Ragione in "the city of the three withouts."

If you ever wanted to touch a medieval mercenary’s three testicles, look no further.