Europe's second largest ossuary wasn't discovered until 2001.

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

Macabre astrological automaton clock dating to the late 1400s.

This grubby wall is said to be one of the Earth's esoteric energy centers.

St. Mary's features one of the most spectacularly decorated cathedral interiors in all of Europe.

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

An underground city of salt.

Sitting beneath an unremarkable residential building is a museum devoted to classic Pinball.

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

Giant WWII fortresses that fired 8,000 rounds a minute, now home to thousands of pigeons.

Baroque celebration of the end of the Great Plague of Vienna.

Trick water gardens from 1619 featuring a 200 piece mechanical theater powered by water.

The topiary maze at the Habsburg hunting lodge.

A small museum filled with over 1,000 clocks, and one particular clock calibrated to run until the year 9999.

This one-time health resort was used by aristocrats around the world.

Castle and secret tunnel withstood a siege until its owner was killed by the Holy Roman Empire, while sitting on the toilet.

One of the greatest movie directors of all time lived and worked in this London flat from 1926 to 1939.

This obscure walkway links Edinburgh’s Old Town with one of the city's prime vantage points.

Remnants of the 16th-century defensive wall still stand unassumingly within Edinburgh.

This long-hidden space above Westminster Abbey now displays the battle gear of the legendary King Henry V.

The most loyal of little dogs, or a Victorian era publicity stunt?

Overlooked by many, the two famous Scottish warriors guard the main gate of Edinburgh Castle.

Two plaques commemorate the site of Shakespeare's first theatre.

Claiming to be the oldest hat store in the world, this historic haberdashery had a hand (and a head) in the creation of the Bowler.