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

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

Experience what life was like in Ireland during the Viking and medieval ages.

In the days before house numbers, these colorful signs held clues about various buildings' purposes.

Trek into the depths of the cave where 17,000-year-old paintings exist alongside 400-year-old graffiti.

This city square is home to Amsterdam's oldest church and a statue honoring Dutch sex workers.

A collection of biblical memorabilia.

Established in 1638 to battle the Black Death, Hortus Botanicus Amsterdam is a treasure trove of rare flora.

This neighborhood of futuristic ball houses looks like an alien settlement in a science fiction film.

These ruins of Francis Bacon's once-magnificent manor are hidden in the English countryside.

A giant roundabout made up of six smaller roundabouts can befuddle the uninitiated.

A seven-century-old jail tells a not-so-pleasant history of crime and punishment.

A museum which takes visitors to the côté obscure of Paris.

France's national museum of scientific and industrial instruments.

19th century pendulum and a clock restored by a rogue group of guerilla artists.

Rows of multicolored bathing huts paint the sand dunes with pops of color.

After years of slow decline, a derelict Gothic castle is now being restored to life.

Peeing dogs guard the Roman hunting goddess atop a fountain at France’s Château de Fontainebleau.

This stunning French estate was so lavish that it landed its original owner in jail for the rest of his life.

Jean Tinguely's bizarre monster sculpture is hidden deep in a forest.

An unusual sand beach in the middle of a forest.

A 4,500-year-old forest is slowly being revealed from beneath the sands of a Welsh beach.

A real-life Professor Snape once taught in this Welsh university building, which students of course nicknamed “Hogwarts.”

A 19th-century funicular railway shuttles visitors up this surprising sea cliff to one of the world's largest camera obscuras.