An expansive complex of subterranean tunnels is all that remains of one of Europe's most formidable medieval fortresses.

A 200-year-old collection of oddities and medical paraphernalia.

This stately monument has been wearing a traffic cone hat for decades much to the delight of the locals.

The elaborate clockwork contraptions in this Scottish gallery create small worlds of whimsy and horror.

"Respectful to the dead, safe and sanitary to the living, dedicated to the Genius of Memory..."

These bleak 800-year-old ruins were once the royal residence of choice for hunting in Sherwood Forest.

After public executions took place at this location, attendants would also attend a local horse race.

The final resting place of England's most notorious bandit.

The remains of a Dominican friary, once one of the largest of its kind in the United Kingdom.

Hundreds of years ago, this lion-shaped door knocker could help a person accused of a crime find temporary safe haven in Durham Cathedral.

A rather grand, but tiny, folly on the banks of the River Wear associated with a Polish count.

In the midst of a living monument to Soviet social engineering, Polish Catholics built this church by hand.

A memorial to the beloved brown bear that served in the Polish army during World War II.

This sprawling concrete suburb of Kraków was designed by the Soviet Union as the model proletarian city.

Beneath Kraków Old Town's main square lies a hologram-filled medieval market vampire graveyard wonderland.

The mummified right fist of a 1,000-year-old saint-king sits inside an ornate golden reliquary.

Tucked away near more famous landmarks lies a statue meant to symbolize the confluence and continuing development of human culture.

A Hungarian pharmacy museum with a box full of mummy powder.

This off-beat, quirky communism-themed bar isn't afraid to poke fun at its history.

Disused seaplane hangar gets a second life as the jaw-dropping home of Estonia's museum of maritime history.

An empty relic of the Moscow Olympics crumbles away in Estonia's capital.

An unassuming London park is actually a pilgrimage site for modern clowns.

A grotesque collection of wax limbs depicting the symptoms of venereal disease.

Where commuters walk through remnants of an ancient Greek necropolis.