A favorite of Amelia Earhart, ranking among those rare bridges that can be crossed without changing sides of the river.

An office built to look like a giant basket.

Three bridges and one giant canyon make up this fantastic Spanish settlement.

This free, take-a-book shop seems like a trick but isn't.

A walk-in working camera obscura produces 360-degree live images of the San Francisco coast.

This suburban house is made of dirt, and almost sparked a revolution in home construction.

A super-sized promotional trick that is now a D.C. landmark.

The famous abolitionist’s preserved estate is one of Washington's finest monuments to its great Black citizens.

Over 100 concrete munitions bunkers are all that remain of a Pennsylvanian village seized by the US government.

The Cold War-era "underground Pentagon" is a sprawling subterranean hideaway for the Defense Department.

This museum glorifies the humble potato.

These century-old beehive-shaped kilns were built to produce charcoal for nearby mines.

A museum dedicated to the history and art of staying clean.

The world's first nuclear power plant is open to visitors looking to role-play a meltdown.

Home to the deepest rift anywhere on Earth.

The perfect spot for a picnic, right next to a giant ballistic missile.

The remains of a doomed Antarctic plane, buried beneath layers of ice and snow, await those willing to do a bit of digging.

The now-abandoned tunnels were built for the transcontinental railroad on the route where the first wagon train entered California.

A remote horde of architectural treasures fit for Indiana Jones.

An abandoned Victorian-era amusement park is rusting away amidst luxury houses.

A Victorian cemetery hidden along a trucking route is all that remains of a 19th century village.

This extensive nuclear fallout shelter built from 42 school buses could house 500 people in its tunnels.

This (occupied) house is 10 feet wide and full of spite.

Enter the world under the hill at this ancient UK burial chamber.