At the tallest peak in Colorado, an electrifying mix of thin air, lightning, and rivalry.

The king of U.S. high points towers over every other peak on the continent.

Three bridges and one giant canyon make up this fantastic Spanish settlement.

This former Baroque palace on the historic Calle Montcada is a rare architectural gem and was once the meeting place of an aristocratic scholarly society.

This lake in the Cascades lives up to its name, disappearing down a hole every spring.

Each spring, a dreamlike carpet of bluebells overtakes the forest floor.

Money made from smuggling sugar helped create this wondrous rock maze in honor of the Prussian Queen Louise.

A stunning, two-tiered waterfall made famous by poets, artists and the legend of a ghost dog.

An intricately carved Viking church overlooks a glistening fjord.

The only theatre in the world constructed specifically for sound movement.

An artsy hidden staircase leads to breathtaking views of San Francisco.

The oldest library in Scotland was built from the remains of a church to hold a churchman's library.

A small island abbey is the final resting place of many medieval Scottish monarchs, including the real Macbeth.

The heads of two giant mythological water horses honor Scotland's horselord past.

Submerged trees jut ghost-like out of an idyllic turquoise mountain lake.

This quaint Italian town keeps losing ground as the sides of its plateau slowly erode.

Perched on a spindly rock spire in a Greek archipelago, this lighthouse would make a perfect wizard's tower.

Medieval ruins on a tiny island amid a flooded lake offer romantic respite to lovers seeking privacy.

Fortified homes of highland warriors that are still in use today.

This cluster of little wooden huts once ground local farmers’ wheat into flour during the days of the Austro-Hungarian Empire.

The most iconic structure in Scotland has been home to bishops, colonels, and Sean Connery characters.

Water and windows define this defensive Italian well.

Sail through this subterranean show cave that is home to a legend that would go on to name nearly everything around it.

This picturesque Umbrian city has a subterranean side that has long remained hidden.