An alchemist's “magic door” stands in the middle of a Roman park.

This abandoned shopping arcade has new life as an art installation.

This historic structure has been used as a mosque, a barracks, a prison, a school, and a bakery.

An often overlooked ancient site in downtown Athens with substantial history (and nature).

Gladiators once walked this ancient, subterranean passage.

Where commuters walk through remnants of an ancient Greek necropolis.

Heralded as the world's first theater, these ruins are often overlooked as they reside in the shadows of the Acropolis.

This ancient Greek place of assembly and marketplace is being revealed layer by layer below the modern Athens cityscape.

A 2,000-year-old computer demonstrates remarkable engineering and astronomical precision.

An ancient octagonal weather station named for the eight Greek gods of wind.

Legend says this sacred tree was a gift from goddess Athena.

This ancient hydrological marvel is now the base of a modern outdoor cinema.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

The world-record holder for the longest bridge stretching continuously over water.

A small park on Bourbon Street features life-size bronze statues of New Orleans musicians.

It was originally part of a "terrible lizards" collection at the 1964 New York World’s Fair.

The unluckiest U-boat in the entire German fleet is now on display in a Chicago museum.

Fragments of architectural wonders from around the globe are embedded in the newspaper building's walls.

Watch the newest land on the planet form before your eyes.

This black shoreline is made up of exploded lava particles.

A series of waterfalls and pools that flow through the 'Ohe'o Gulch and into the ocean.

The air force base preserves its scars from the Japanese attack on Pearl Harbor.

This museum of Hawaiian and Polynesian culture is the legacy of the last descendant of the Kamehameha Dynasty.

The only royal palace on U.S. soil has been a territorial capitol, a military headquarters, and a prison for a queen.