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

This Slovak bridge is known both for its connection to a national uprising and its UFO-shaped eatery.

This spaceship sculpture in the middle of the Slovakian capital looks like it just crash-landed.

The former private quarters and office of Dr. Sigmund Freud now hosts a museum housing the works of the founding father of psychoanalysis.

This Polish cave has housed a dragon, a brothel, and an enduring legend.

From Austrians to Nazis to Soviets, this historic Budapest fortress has a history as complex as the city itself.

A Trabant car, a kangaroo statue, and a plethora of plants take over this abandoned-factory-turned-bar.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.

A surreal statue honoring Prague's favorite literary son.

This spooky statue sits outside a famous Prague theater.

Despite attempts by local police to discourage it, Beatles-inspired graffiti has been a means for artists to air grievances for decades.

What looks like a suicide in progress is actually a statue of Sigmund Freud.

This tipsy office building in downtown Prague was originally called “Fred and Ginger.”

Around 100,000 bodies are buried below the medieval headstones, many of which mark graves with multiple bodies stacked up to 12 deep.

Macabre astrological automaton clock dating to the late 1400s.

Some of the smallest works of art in existence.

This bird-loving brewery is situated in an old municipal bathhouse, nestled beside a 300-year-old windmill.

The last Victorian market in Belfast.

This Victorian-era public house has set the standard for pub-style elegance for over a hundred years.

A mysterious plaque to the even more mysterious "Fr. Pat Noise," killed in "suspicious circumstances."

The modern birthplace of Irish freedom.

The 19th-century pharmacy (now a used bookstore) was featured in James Joyce’s "Ulysses," and has changed very little to this day.

The comedy and tragedy of Oscar Wilde is preserved in a Dublin park, captured in a sculpture of colorful stone.

One of Ireland's most infamous prisons for rebels including men, women and children.