A line of abandoned, alien-like fortresses dot the mountains of North Italy.

Ruins of a 10th century church tucked away deep in a botanical garden.

On top of Gibbet Hill lie the ruins of a lavish turn-of-the-century estate that never quite came to be.

A spiral staircase twists to the top of this unusual Czech lookout tower.

A Victorian Gothic masterpiece housing a world-class collection of rare books and manuscripts.

Home to three historic ships from the age of Vikings.

Stockholm's decidedly unique public transit system has doubled as the world's longest art gallery for decades.

In this historic region, homes and churches are carved into ancient volcanic rock formations.

The most powerful waterfall in all of Europe.

Enchanting cave with a river crashing through the roof.

35,000 grape hyacinths flow like water down a garden hill.

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

Hidden just under the waters around this Turkish island are the ruins of a once great city.

This dramatic landscape hidden on the Isle of Skye looks as though you've stepped into the magical realm.

One of the most breathtaking railways in Europe also takes one of the steepest climbs, from fjord to mountain plateau.

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

The highest point in Washington state is a volcano covered in glaciers.

The highest point in Virginia can only be reached by passing through ponies and flowers.

Despite a legend that says this highest peak in Oregon was climbed in high heels scores of people have died on its slopes.

The highest point in North Carolina and the United States east of the Mississippi River, Mount Mitchell is named after argumentative explorer Elisha Mitchell.

Minnesota's highest point is a scenic vista marked by a plaque and armies of mosquitoes.

Inspiring Herman Melville and Henry David Thoreau, Mount Greylock in western Massachusetts is the highest point in the state at 3,491 feet above sea level.

The highest point in Maine is a grand gift to the state citizens that also happens to be one end of the Appalachian Trail.

Earth's tallest volcano is sacred to Native Hawaiians, and home to a dozen world-class observatories.