A breathtaking bridge that crosses a vast gorge over a river's torrents, and has a tale of a devil architect attached.

Large Hadron Collider and the Birthplace of World Wide Web.

A historic observatory precariously perched at the "Top of Europe."

This memorial commemorating fallen Swiss Guards of the French Revolution has been called the saddest stone in the world.

This is not only one of the oldest collections in Europe, but also possibly the most beautiful.

These spooky and unusual stone formations create an underworldly landscape.

This 170-year-old Swiss guesthouse built into the side of a mountain is best accessed by a cable car.

Caves famous for the dragon-slaying saint who lived there.

This amazing pedestrian suspension bridge in the Swiss Alps would give Indiana Jones nightmares.

The tallest outdoor elevator in Europe rockets passengers on a dizzyingly precarious ride to the top of a mountain.

This lovely little bridge hidden in a Switzerland gorge is essentially a fairytale.

Wander among the abandoned ruins of this once-powerful medieval town.

One of the oldest lighthouses in the world, this structure was built more than 800 years ago.

The eerie remains of one of Ireland's oldest castles, said to be haunted by the ghost of a woman who brings ill fate.

An elaborate Romanesque archway, built right before the British occupation of Ireland.

Ireland's most northerly island is hauntingly beautiful. Its lighthouse was the last glimpse of home for many Irish emigrants bound for the U.S.

The remains of a concrete ship sit on a sandbank between Ballina Quay and Belleek Woods.

At the time of its construction, this hydroelectric power plant was the largest in the world.

The ruins of a monastery that dates to the 7th century.

The remains of a majestic house that was once stood in the crosshairs of the Irish Republican Army.

This 18th-century fort surrounded by a moat was used to store gun powder and ammunition, and now sits in the middle of a large part in Dublin.

These moss-covered medieval ruins tower atop the smallest of Ireland's Aran Islands.

A stunning medieval castle owned and restored by the famed actor Jeremy Irons.

Impressive mining ruins overlook a spectacular view of Ireland's Copper Coast.