This imposing Masonic temple a mile from the White House was the first public library in Washington, D.C.

A derelict bit of transportation infrastructure hidden in the woods.

One of the dwarven trees dates back to 1625 and survived the Hiroshima bombing.

Home to items never before seen by the public.

The southernmost point in the United States is a beautiful place to look at but a deadly place to wade in.

These picturesque Hawaiian falls are home to a rare species of fish that uses a special sucker to climb up cliffs.

Hide from the tourist hordes in these relatively unknown, and unguarded lava caves.

Earth's tallest volcano is sacred to Native Hawaiians, and home to a dozen world-class observatories.

These ancient sacred grounds granted amnesty to those who managed to reach them.

A controversial memorial at the place where Captain Cook met his violent end.

Under the right circumstances, this waterfall in Yosemite briefly turns a luminescent fiery orange.

A glimpse into the lives of the the Miwok and Paiute people in Yosemite National Park.

The interior of the Overlook Hotel in "The Shining" was based on this Yosemite original.

This Yellowstone geyser may not shoot as high as the nearby Old Faithful, but it erupts for considerably longer.

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.

An immersive environment that is part haunted house, part choose-your-own-adventure, and part jungle gym.

Explore the largest pure gypsum deposit in the world, and go dune sledding while you're at it.

See massive fossils that are over 200 million years old in northeastern Arizona.

A museum dedicated to the alleged Roswell Incident.

The ancient dwellings of the Puebloans, located in the cliffs of majestic mesas.

When ecosystems collide in the arid Southwest.

Twenty-seven massive radio antennas on the high plains of New Mexico search for life on other planets.