Housed in a memorial lighthouse, this museum relays the history of surfing, beginning with the antics of royal Hawaiian teenagers.

This concrete ship has had four careers - World War I tanker, floating amusement park, fishing pier, and artificial reef.

This historic hotel invented the chocolate brownie.

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

A place to eat for on-the-run agents and espionage enthusiasts.

A modern mechanical planetary system, part of a 10,000 year clock.

A collection of 20th-century automata, penny arcade games, and musical contraptions.

The arch that celebrated the completion of the Lincoln and Victory highways.

Singing sand that stands as the final remains of an ancient lake.

Officially named the "Loneliest Road in America," this barren stretch of Nevada road offers almost nothing but sky and open fields.

Home to the deepest rift anywhere on Earth.

A sculpture made of 10 Cadillacs as a monument to the “Golden Age” of the American automobile.

Just a man taking his prehistoric pet for a stroll.

The world's largest mountain carving could fit all of Mount Rushmore inside it many times over.

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.

An architect's childhood fantasy treehouse made real.

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.

The first declared National Monument in the United States.

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

The only road through the heart of Glacier National Park.

This giant temperature attraction created some giant electric bills.