This natural marble cave is one of only five national monuments in Oregon.

Next to Salt Lake City's Assembly Hall stands a tribute to some unlikely heroes of early Mormon settlers.

A 200-year-old bar in the historic French Quarter refuses to give up its place in history, nor its role in securing ours.

A graceful natural rock formation stands astride the point where the Gulf of California meets the Pacific Ocean.

This sidewalk monument honors more than 50 civil rights activists who helped change the face of America.

The small town of Poulsbo in Washington state is the next best thing to the Kingdom of Norway.

This recently restored timepiece has stood all around Kansas City.

Once the smallest park in the national system.

The gambling entrepreneur who built a city was also an avid collector of classic cars.

This Las Vegas casino boasts one of only three spiral escalators in the United States—an engineering wonder.

A bizarre example of collective behavior resulted in thousands of shoe prints in Vegas parking lots.

An ode to one of the first concerts broadcast via satellite.

This balancing rock is one of Utah's most unusual geological formations.

A strenuous, unofficial trail leads to spectacular views in one of America's most remote national monuments.

This sinkhole in the Arizona desert is filled with carbonated, arsenic-rich water

Once the product of an inexplicable gold strike, this ghost town is now home to one man and his love of classic machines.

This secluded date farm can be reached only by following a bumpy, single-lane desert road.

The second-largest giant sequoia in the world.

Beneath the southern end of the Golden Gate Bridge is the “Gibraltar of the West Coast,” a fort built to protect the San Francisco Bay from naval attack.

This crumbling Death Valley mining complex was known for its use of giant, 20-mule team wagons.

One of the largest helium balloons in the U.S. is a 112-foot ginormous orange.

The cobbled together compound of a deceased artist which now serves as a filming location.

This quirky UFO-shaped curiosity is often mistaken for the airport’s control tower.

The California capital city once stood 10 feet lower than it does today.