Once the site of the Hawaiian monarchy, this building was originally designed as a palace.

The only royal palace on U.S. soil has been a territorial capitol, a military headquarters, and a prison for a queen.

Air Force Academy Chapel made of 100 identical tetrahedrons works to inspire those of all religions.

A small metropolis of Pueblo cave dwellings have been carved right into the hillside of this national monument.

This popular pilgrimage site offers a hole filled with holy healing dirt.

A natural formation that resembles a camel resting in the New Mexico desert.

The oldest continuously occupied public building in the United States.

This innocuous New Mexico storefront was once the secret jump-off spot for Manhattan Project scientists.

Wedding chapel's mysterious spiral staircase said to be miraculously constructed.

The fifth-longest natural arch in the world, and the longest outside China.

These tall, red sandstone pinnacles outside Moab are often forgotten amid their more famous neighbors.

This nearly abandoned town was once a thriving mining community until a series of fires.

The remnants of the base where US Army troops learned how to fight in extreme conditions.

Around half a million years ago, these magnificent columnar basalt cliffs were formed from cooling lava.

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.

An architect's childhood fantasy treehouse made real.

A 6-mile-long lake created by an apocalyptic seismic event and the deadly chain reaction that ensued.

The only natural lake in the world that drains into both the Atlantic and Pacific Oceans.

Devilish landscape, once cinema home to giant alien bugs, now derelict roadside attraction.

A popular rock that acted as a waymarker for American pioneers.

This mining town boomed in the Atomic Age when uranium was gold, only to be abandoned when the industry collapsed.

A devilishly named gorge that was a sign of salvation for many pioneers.

The burial grounds of a secret society includes fences topped with fake Tesla balls.