Poland's oldest salt mine has nearly everything one needs to live underground forever.

This uber-quaint Polish village is known for its habit of painting elaborate floral motifs on just about everything.

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

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

This centuries-old wooden wonder was built in less than a year and is one of Europe's largest timber-framed churches.

A mysterious structure left behind on the Polish mountainside, sometimes called "Hitler's Stonehenge".

One of the largest amphitheaters in Europe is a former Nazi gathering place that still stands today.

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

The former Nazi concentration camp stands as a museum to remember this dark chapter in European history.

Real bones which are said to have belonged to a Polish dragon.

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

An underground city of salt.

The walls and ceiling of this Polish church are decorated with thousands of skulls, with another 21,000 skeletons just below.

Since 1874, this macabre collection has developed into a museum devoted to Scotland Yard's mementos of dastardly deeds.

This East End pub gained notoriety as the site where gangster Ronnie Kray publicly shot a rival.

A faded reminder of what was once a common sight in London during the Blitz.

This macabre painting of a Shakespearean scene looks like something out of a nightmare.

The ritual has been performed uninterrupted for nearly 700 years.

The wooden telephone box hidden away in London's Piccadilly was the original prototype of the iconic kiosk.

The 2,000-year-old beam is tucked within the pedestrian entrance to the old London Bridge.

These morbid carvings remind churchgoers of the inevitability of death.

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

The secret wartime bunker built on the platforms of an abandoned Tube station.

These official units of measurement—including chains and perches—lie hidden beneath tourists' feet in a popular London hub.