The ruins of the largest gladiatorial school in Rome are largely hidden under modern streets.

This is the oldest Roman-made bridge in the city still existing in its original state.

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

This small, ancient Roman temple was once a church dedicated to the patron saint of penitents.

The "Great Sewer" of ancient Rome is one of the oldest sewer systems in the world, and is still in use.

The studio built by fascists in the hopes of "reviving the film industry" with the occasional propaganda film opportunity thrown in.

A 16th-century horror show built in a lovely Italian garden.

Niagara Falls holds a special place in Nikola Tesla's history, so they put a statue on it.

A tunnel that brings more than a century of history to life from the deepest parts of the Niagara Gorge.

This Niagara Falls tourist trap is a world bright with neon and curiosities that will inspire love, hate, or a mixture of both.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

Tourists often confuse this beautifully ornate former cigarette factory for a mosque.

This Dresden church was purposely rebuilt Protestant after being demolished in World War II.

In addition to fine dairy products, the world's most beautiful milk shop also offers a feast for the eyes.

When the rain falls, this drain system turns into a musical instrument.

Pilgrimage site for star-crossed lovers.

A Black Forest cuckoo clock theme park features one timepiece big enough to walk inside.

This medieval castle overlooking the Elzbach river looks just like it did hundreds of years ago.

The last bastion of Roman presence north of the Alps looms over a German town.

The birthplace of Karl Marx is now a museum dedicated to the communist revolutionary's life and work.

This stone commemorates the island's launch into international aviation.

Partially collapsed lava tube and cave system complete with concert hall, underground pond, and unique albino crabs.

This beautifully verdant lagoon is tucked below a massive volcano in a crater atop a black pebble beach.

This local emblem is the oldest and largest dragon tree in the Canary Islands.