This 20th-century replica of a 13th-century castle has itself fallen into ruin.

This massive subterranean fissure is known as the "underground Grand Canyon."

Hidden beneath a bridge, this waterfall is known for the large amounts of graffiti painted on its base.

See just what life was like in a 19th-century prospecting town.

The remains of an idyllic small town built for the film 'Big Fish' still stand around a rundown main street.

This fortified L-shaped tower is the ancient seat of clan Hannay.

The oldest restaurant in Portland serves fiery coffee cocktails and an astounding amount of turkey.

Two thousand artifacts from around the world collected by one woman who loved to travel.

In the 1950s, two women saved this grand theater in the Colorado mountains from demolition.

A 98-room castle in the middle of Toronto that bankrupted a 19th century electricity multimillionaire.

The enormous 250-room Vanderbilt mansion conceals hidden doors and secret passageways.

Rustic natural hot springs in the deciduous rain forest.

Rushing water plunges over a 100-foot drop created by an ancient lava flow at this majestic waterfall.

The trunks of 3,000 year-old trees lurk beneath the surface of this crystal clear lake in Oregon.

One of the most scenic stretches of road in America winds between some of the country's oldest trees.

Quite simply the largest tree in the world (by volume).

This geothermal hot spring hides beneath a slowly growing mineral dome.

Hollowed out cedar log tubs set in an ancient towering forest.

Towering basalt columns, a creation of fire and ice.

The deepest lake in the United States, and once the site of epic destruction that lives on in legends.

A winding path built in secret on the edge of the continent.

A roaring, awe-inspiring double cascade of icy water flows through woodland Oregon like something out of a Tolkien novel.

Under the right circumstances, this waterfall in Yosemite briefly turns a luminescent fiery orange.

Crystal clear lake with a shoreline of travertine located in a Colorado canyon.