A guitar mounted on a wall in Temple Bar honors the Irish musician.

The somber sculptures commemorating Irish Famine on the river Liffey in Dublin.

Tiny silver and copper fish set inside blue-green lights are like windows to the underwater world.

Dublin's most modern, visually spectacular bridge is modeled after Ireland's national emblem.

The 19th-century pharmacy (now a used bookstore) was featured in James Joyce’s "Ulysses," and has changed very little to this day.

An enigmatic monument to the Irish revolutionary who plotted an uprising against British rule.

The enchanting archway is the only surviving portal into Dublin’s lost medieval wall.

A long-buried ancient ruin unearthed right in the middle of the city.

One of Jeff Koons’s largest sculptures and his first commemorative work.

Remains of Roman amphitheater hidden in a sleepy quarter of Paris.

This 400-year-old tree is actually an immigrant from North America.

This bridge was constructed from the rubble of the infamous Bastille.

The oldest and smallest cemetery in Paris is only open to the public twice a year.

Centuries of human activity have forged an eerie landscape of ruins and craters on an exposed and windswept hilltop.

A prison with a more than 200-year history.

This pub can leave even the sober feeling slightly unsteady.

The oldest inn in England served brew to the crusaders.

Built by the patron saint of illusionists this Elizabethan manor house is riddled with secret cubbies for hiding priests.

A minotaur, a labyrinth, and a dubious restoration pull in visitors from around the world.

You can spot this teeny tiny stained-glass window from the Bonifacius bridge.

The compass on its front was a handy tool for 17th-century merchants who needed to know the direction of the wind.

Go back 50 years with a turn on one of the park's carefully restored vintage fairground rides.

Huge winged monument in the United Kingdom.

An engineering error ensured this cavernous 350-foot-long subterranean thoroughfare was never used as intended.