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

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.

A French chateau, failed utopian community, odd museum, and Stonehenge replica in rural Washington State.

A Roman-style column in Oregon hides a spiral staircase inside.

Granting the right of way to ships over surface traffic since 1917.

A museum dedicated to the history and exploration of both popular music and science fiction.

Historic site where Native American hunters once trapped and killed buffalo.

The only road through the heart of Glacier National Park.

After Havre burned down, the best place to build was under the ashes.

Home to the deepest rift anywhere on Earth.

Native Americans built this circle of stones, which was used to predict astronomical events.

The last physical evidence of the Lewis and Clark trail is one of their autographs etched into this giant rock.

New fungal and bacterial species call this deadly lake home.

An entire town preserved as a historic landmark.

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

A beautiful geyser under environmental threat.

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