The walls of America's oldest masonry fort famously "swallowed" cannonballs.

This recently rediscovered Civil War-era submarine was the first to ever sink an enemy ship.

The first public building in Savannah to offer air conditioning was a luxurious cinema that still operates today.

Local myth claims this is a Sears catalogue home with its windows installed upside-down.

A statue honoring 44 continuous years of greeting passing ships.

This kitschy tavern is also home to rare early editions of "Treasure Island."

The concrete shell of an industry giant remains as a playground for graffiti artists, auto scrappers, and paintball warriors.

The plants form a living library and laboratory for researchers and students at Michigan State University.

An organ located deep within a cave, whose "pipes" are the geological features of the cave itself.

A 90-year-old underground water reservoir offers a more industrial kind of tranquility.

James Turrell's total color immersion art installation, hidden on the top floor of a luxury handbag shop.

Shoreline strewn with the remains of ghostly fallen trees.

You might know it as the Overlook Hotel, but the inside is not going to be familiar.

The U.S. Navy's last diesel-electric submarine rests half-submerged in the middle of Portland.

This extravagant Art Nouveau rest stop features a million-dollar view of the Columbia River.

Where Nor'easters go to die.

This gorgeous beach hides behind two headlands in Oregon's Ecola State Park.

A massive sea stack famous for its appearance in The Goonies.

Two massive rock outcroppings on the Oregon coastline.

No one knows how this Pacific Northwest spruce tree came to have so many trunks.

This unassuming cheese empire in rural Oregon churns out more than 150,000 pounds of cheese each day.

The mysterious 855-foot zigzagging stone wall has been baffling people for centuries.

At Macon’s oldest cemetery two members of Allman Brothers are buried side by side.

One of the largest-ever mental hospitals now sits abandoned, surrounded by 25,000 unmarked graves.