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

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

High atop the Eiffel Tower is a small apartment built exclusively to entertain the science elite and make the rest of Paris jealous.

The celebrated eyesore created by starry-eyed sweethearts.

Daily jousts and dancing barrel makers in Munich's mechanical clock.

This magnificent museum claims to house the cranium of a disciple and the skull of a pope.

The prototype for all Nazi concentration camps.

A little sculpture with a large wardrobe.

The handiwork of a underdog clockmaker who solved an impossible problem for an Empire, and forever revolutionized seafaring.

Thanks to modern navigational tools we now know that the true prime meridian runs through a park next door.

Scattered throughout London are ancient remnants of the city's former bounding wall.

Used as an example in one of the first dictionary entries for "museum" in 1706.

A theatre built to house the rowdy Oxford graduation ceremonies became the stage for a debate about God's existence.

Go inside to really appreciate this 500-year-old technological masterpiece.

Macabre astrological automaton clock dating to the late 1400s.

The first archaeological site discovered by aerial photography.

Famously misunderstood wonder of the ancient world

The oldest working mechanical clock in the world.

One of Europe's oldest libraries.

This 11th century tower is said to be the oldest building in Oxford.

The granddaddy of English geoglyphs dates back to the late Bronze Age.

Europe's largest prehistoric mound – burial site of a legendary king?

The atmospheric road was never meant to be so creepy.

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