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

A boulder in the Churchyard of Down Cathedral marks the legendary burial place of "The Apostle of Ireland."

This World War II relic let Allied pilots know they were entering neutral airspace.

A series of stained glass artworks that depict images of the hit TV show.

This massive monument has been telling the time for 150 years—at a slight angle.

A giant sculpture of the legendary "Salmon of Knowledge" celebrates the return of fish to Belfast's River Lagan.

This strange statue features a bust of the famous composer plopped atop a woman's body.

It was once nicknamed "the most bombed hotel in Europe."

The ruins of this medieval castle in Northern Ireland have inspired artists from C.S. Lewis to Led Zeppelin.

This short bridge is the only thing connecting a tiny Irish island to the mainland.

Northern Ireland's Brobdingnagian stepping stones.

The "lost friend” is the most famous of the six moai statues that were removed from Easter Island.

"We gonna rock down to Electric Avenue, and then we'll take it higher..."

An artistic tribute to the famous singer, just around the corner from where he was born.

Eighty million natural history specimens call this gargantuan museum home.

The giant birds honor two native North American species.

Every hour the doors open to reenact the legend of the heroic mayor who saved his town by drinking a gallon of wine.

Horrifically creative torture devices and shame punishments line the walls of this chilling museum.

This 22-floor tower's Skydeck offers panoramic views of Amsterdam.

A floating cat sanctuary on an Amsterdam canal.

Lumps of significant stone from around the world surround a flaming monument for peace.

The modern birthplace of Irish freedom.

These engineering masterpieces are a dominant feature of the Belfast skyline.

The ship built to ferry passengers and goods to the doomed Titanic is now the last remaining White Star Line vessel.