At Washington's Dulles Airport is a satellite museum (no pun intended) with three quarters of a million square feet of aircraft history.

This isn't your average roadway—it's actually a National Park and a transportation pioneer.

A former major munitions plant that has been converted into a sprawling art space.

This stately building in Alexandria, Virginia was built by Freemasons to honor one of their most famous members.

At 207 feet, one of the world's longest continuous escalators.

400 million-year old limestone caverns nestled in the Ozarks served as shelter and a hideout for cultures throughout North American history.

This national park on the shore of Lake Michigan features remarkable dunes that lie at the heart of a Chippewa legend.

Island where motor vehicles are banned -- home to the only carless highway in the United States.

The only structure left with direct ties to the Salem witchcraft trials of 1692.

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

This 4,000-foot-diameter hole is touted as "the most well known, best preserved meteorite crater on Earth."

Florida might be at its most surreal in this museum devoted to the famed Spanish artist.

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

The highest bridge in America was built for an almost unnervingly small amount of money.

Strange red rock formations that have been attributed to a higher power for hundreds of years.

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

Megachurch turned Catholic church comprised of 10,000 glass panes.

A Swedenborgian glass church surrounded by redwoods sits perched atop a massive landslide area.

These delicate buggers are some of the rarest fossils that have bubbled up from the Tar Pits.

Remants of foundations, streets, and streetcar tracks inhabit the cliffs where a landslide occurred in 1929.

Quirky water tower advertises the long-gone Brooks Tomato Products Co.

Funded by John D. Rockefeller, this is one of the earliest, and most beautiful, shopping arcades in America.