One of the most popular megalithic sites in Ireland stands as a humbler version of Stonehenge.

A tribute to the Polish insurgents who fought in the failed attempt to end their city's Nazi occupation.

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.

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

An underground city of salt.

Vast stretch of tide-pools with a unique Moroccan charm.

Morocco's Argania trees are infested with nut-hungry goats.

A daring D-Day assault by U.S. Army Rangers is commemorated atop the high cliffs of this strategic point.

Remains of the artificial harbours invented for the Allied invasion of Normandy can still be seen at sea.

The world's tallest bridge is also possibly the most elegant.

Historic medieval fortified city in southwest France.

French commune at the heart of conspiracies.

The world's largest solar furnace uses 10,000 mirrors to concentrate the sun's rays to generate power.

Immortalized by artists, this church incorporates a medieval lighthouse into its shoreside structure.

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

Macabre astrological automaton clock dating to the late 1400s.

A crumbling ghost town with prime views of the dam that doomed it.

An ancient necropolis of magnificent tombs.

For nearly 2,000 years this church has been waging war on local snakes by importing cats.

A moving memorial to the fallen and missing from WWI trenches.

A little sculpture with a large wardrobe.

Climb inside an iron crystal magnified 165 billion times its normal size.

This natural crater along the coast of Jersey may take its name from the devil statues who have watched over it.