This daunting 1st century fortress was purportedly the site of one of the most dramatic revolts of the Jewish-Roman wars.

Less a museum than a bizarre fantasy world created by artists and engineers.

Giant, natural amphitheaters made of delicate geological formations called "hoodoos."

Ruined 11th century abbey built by King David I in Edinburgh, Scotland.

Four glass boxes hover over 1,000 feet in the air to give visitors an unparalleled view of Chicago.

The world's longest known cave system.

Home to items never before seen by the public.

This 4,000-foot-diameter hole is touted as "the most well known, best preserved meteorite crater on Earth."

The first declared National Monument in the United States.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

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

The only structure left with direct ties to the Salem witchcraft trials of 1692.

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

A sharp bend in a dramatic river canyon cut through red rocks.

A bizarre house filled with an astounding array of collections.

The last remaining example of the boatmen's perches that once dotted the south bank of the Thames.

J.R.R Tolkien, C.S. Lewis, and other "Inklings" met at the Oxford pub to discuss the now legendary fantasy stories they were writing.

Mrs. Mallard and her brood are a beloved fixture in Boston Public Garden.

Electrical pylon in the shape of Disney's beloved mouse.

A luxurious 1880s hotel with its fair share of Tiffany stained glass, Edison electricity, and of course, ghosts.

A swamp that was the site of prehistoric water burials also managed to preserve its corpses for millennia.

A building so large that it has its own weather.

This Florida sinkhole hides a rainforest-like micro-environment in its depths.

Arrr! The most authentic collection of pirate artifacts in the world... matey.