The remains of a 1st-century aristocratic Roman town house featuring beautiful well-preserved mosaics.

Overshadowed by other, more famous Maltese catacombs, this ancient burial chamber has one of the best examples of a ritual agape table.

Burial grounds for more than 1,000 bodies deep under the modern town of Rabat.

This prison on the Maltese island of Gozo is almost 500 years old, and they have the graffiti to prove it.

This spectacular dome managed to survive after being bombed in World War II, in an event known as the "Miracle of Mosta."

These lesser-known Maltese catacombs date back over 1,700 years.

These temples are among the oldest free-standing stone buildings in the world.

Two geological phenomena in one precarious locale: a towering stone window, and a deep blue void.

The river-powered ferry dates back to 1970s.

One of the world's largest amber altarpieces is housed within this reconstructed medieval church.

This one-of-its-kind shipyard brings the 12th-century Viking Age back to life.

400 million-year old limestone caverns nestled in the Ozarks served as shelter and a hideout for cultures throughout North American history.

One of the world's earliest skyscrapers.

The Old Courthouse takes visitors on a captivating trip through St. Louis' timeline.

A creepy sculpture of a decapitated head invites viewers to see St. Louis through its empty eyes.

Less a museum than a bizarre fantasy world created by artists and engineers.

This ancient Irish tower could easily have stood in for Rapunzel's prison.

A rocky Irish outcropping with a history of wealth, conflict, and ruin.

Behemoth, cannon-like telescope operated by generations of Irish earls.

An Irish peat mine has become a stunning sculpture park.

The oldest pub in Ireland may also be the oldest surviving bar in the entire world.

Dublin's most modern, visually spectacular bridge is modeled after Ireland's national emblem.

The modern birthplace of Irish freedom.

The block of aged dairy is probably still edible after 2,300 years in a peat bog.