Built following the War of 1812, this fort has withstood hurricanes for centuries.

By day this New Orleans square is for pedestrians, but by night it is a kingdom of kittens.

Almost half-way between the Equator and North Pole.

This erect, phallic geological spire wasn't always named so domestically.

The world's tallest doric column is this Ohio monument to a naval victory in the War of 1812.

Island where motor vehicles are banned -- home to the only carless highway in the United States.

This Arkansas town is known for its gangster history, its healing waters, and now its brews.

The farm where one of America's greatest leaders was raised is now a well-appointed landmark.

Hidden within an idyllic suburban garden is a memorial dedicated to the victims of a terrifying spree of killings committed on U.S. soil.

The highest point in the state of New Hampshire, and while unlikely "the worst weather in the world," it sure seems that way to hikers.

This candy-striped tower is the farthest east you can go in the United States.

A 60-room castle constructed by a horse-racing heir.

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

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

Down the road from where the Wright brothers lifted off is another flight tribute practically hidden from sight in the woods.

A castle inspired by medieval architecture is hidden in the woods of Connecticut.

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

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

Home to the deepest rift anywhere on Earth.

A beautiful geyser under environmental threat.

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.

Legend has it the commander of the defenders drew a fateful line in the dirt with his sword just before the final battle.

Enchanting gardens surround a derelict mansion, all hidden in plain sight behind a stone wall.