This fort down the Potomac from Washington, D.C. was once the only defensive fort protecting the capital.

A wild west cemetery in Tombstone, Arizona, provides a window into the Old West.

An old saloon in the West filled with history, and according to some, a few dozen ghosts.

A spiritual vortex among the red rocks in Sedona.

Ninety feet off the valley floor is an ancient dwelling put under protection of the U.S. government by Teddy Roosevelt.

The former home of the Nobel Prize-winning American writer is now home to dozens of six-toed cats.

These remote Florida islands have a history of sea turtles and sunken treasures, and one of the world's largest coastal brick fortresses.

The last holdout of a pre-Civil War rebel who took the matter of slavery into his own hands.

"Girl in a Wetsuit" is what happens when a sculptor has to find a way around a 100 year old copyright.

A pixel art killer whale is frozen mid-leap in this Vancouver square.

One of nature's most well-scheduled phenomenons resides in Wyoming's Yellowstone National Park.

The largest hot spring in the United States is, as the name suggests, a stunning show of natural color.

A beautiful geyser under environmental threat.

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

Now a museum, this building was once a 14th-century monastery and the place where the founder of the Dutch nation lived and was assassinated.

A miniature city, once ruled by the Queen of the Netherlands.

Amsterdam's former hotspot for public executions and dissections.

Birthplace of the "Cat in the Cradle" and a cluster of iconic, original windmills that let the Dutch tame the seas.

This small town in the Netherlands has no roads but instead, miles of canals and over 100 bridges.

Go inside to really appreciate this 500-year-old technological masterpiece.

Classic game cookery takes center stage at what's widely considered London's oldest restaurant.

These mysterious Viking chess pieces spent centuries hidden on a remote Scottish island.

An architectural oddity hides in plain sight on this iconic London bridge.

Tucked away in the Tower of London is the weapon once used to execute high-profile prisoners.