A former major munitions plant that has been converted into a sprawling art space.

This isn't your average roadway—it's actually a National Park and a transportation pioneer.

This lovely picnic spot featuring thunderous jet landings is an aircraft spotter’s dream.

At 207 feet, one of the world's longest continuous escalators.

This war hero's old shop remembers the fine line between medicine and quackery during the Revolutionary War.

One of corporate America's best-kept secrets is also one of the most publicly displayed.

The walls of America's oldest masonry fort famously "swallowed" cannonballs.

A spiritual vortex among the red rocks in Sedona.

An exotic wildlife habitat right off The Strip.

A peculiar mansion built by the troubled heir to the Winchester Rifle Company fortune.

The semi-reclaimed ruins of this canal were once part of an ambitious plan to reroute the mighty potomac.

The bizarre headgear looks like it was made for a fool, not a king.

A 600-year-old mini shrine guarded by a sword-wielding knight hides in a crumbling cliff face.

Cycle the solar system—from the sun to Pluto—right here on earth.

Bronzes and busts that once stood in the city's main squares are now relegated to a small hidden courtyard.

This ominous Albanian fortress houses tanks and downed planes as a reminder of their victories over Western imperialism.

An Albanian monument to the Communism that nearly crushed the country is now a crumbling wreck.

A beautiful mountaintop mausoleum devoted to a Montenegrin icon can't seem to make everyone happy.

These historic defenses ensured the city within would survive hundreds of years of occupations, sieges, and invasions.

The National Railway Museum in York is the largest railway museum in the world, attracting almost 1 million visitors per year.

The name of this suspended sculpture is Latin for "high horse," which is exactly what it is.

One of three sites in England that house the National Collection of Arms and Armour.

Artists have long been drawn to these atmospheric 12th-century ruins.

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