A towering spire in the fortress of Kalemegdan honors the victorious armies of Serbia during their struggles against the Ottoman Empire.

Inat Kuća, or "House of Spite," is more than just an oddly named restaurant.

Ancient serpentine sacrifice holder that has stood the test of time.

A fountain standing as a testament to a doomed alliance.

The most metal church of all time was built in record time because of an international, pious pissing contest.

This remarkably well-preserved Egyptian plinth is pretty well traveled for a giant piece of stone.

Five sultans and their families rest in eternal splendor, teeming with overlooked beauty and drama.

A marvel of Byzantine engineering under the streets of Istanbul.

The deepest underground city in Turkey was designed to protect 20,000 people behind massive stone doors.

This incredible stone temple is a monument to death, victory, and fantasy architecture.

Lyon, France is home to two remarkably preserved Roman theaters, one dating back to 15 BCE.

Lyon's miniature version of the Eiffel Tower was built as a statement in support of French secularism.

Hundreds of hidden passageways weave through the old quarters of Lyon.

Ever-growing collection of devils in art.

The silly symbol for an underground protest group is now scattered around the city.

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

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

Museum dedicated to the terror regimes of Hungary.

An Italian geologic wonder that served as the inspiration for the landscape of Dante's hell.

The mummified heart of a saint lives on in this church—after a brief hiatus when it was stolen.

An Irish church where an 800-year-old mummy is reaching out of his coffin as if to shake hands.

The atmospheric road was never meant to be so creepy.

Northern Ireland's Brobdingnagian stepping stones.

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