Rare recess caves fill this unbelievably beautiful Ohio park.

An abandoned aircraft sits submerged in a lake in the Alaska wilderness.

An impressive collection is dedicated to the legendary beast.

World's largest college campus includes a wildlife sanctuary and a former movie set on more than 28,000 acres.

Follow the steps, and this roadside artwork will teach you how to dance.

The fine fabric handwoven at Biltmore Industries was once coveted around the world.

This rare basilica nestled right in downtown Asheville is an architectural marvel, inside and out.

This psychedelic tromp l'oeil seems to be beckoning drivers to crash into a wall.

The world's largest fire hydrant is supposedly tornado-proof.

This titanic steel chain linking two buildings was installed without permission but instantly beloved.

An old train trestle re-imagined as an Egyptian obelisk.

They call this long foot bridge a swinging bridge, but really it's the bouncing you have to watch out for.

An elegant Georgian cemetery best known for the grave of the little girl whose murder on Christmas Day remains unsolved.

Like Mars, but much closer.

This intricate Hindu temple is the largest of its kind outside of India itself and was constructed like a giant puzzle.

Hidden beneath the streets of London is a secret subway that only carried mail.

Not merely a museum – but a whirring powerhouse that offers a subterranean peek into the heart and soul of cable car operations.

The one-time watch house for incoming ships at the Golden Gate now stands abandoned and hidden in trees.

Relics of the 1894 Midwinter Exposition continue to delight visitors today.

The seawater playground of gilded-era San Francisco burned to the ground in 1966.

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

A winding path built in secret on the edge of the continent.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

A huge musical instrument played by the ocean.