A 2017 crowdfunding campaign saved this historic castle from being destroyed.

You can find America's highest suspension footbridge at Grandfather Mountain in North Carolina.

Over time, this castle grew to encompass the entire island.

It's unclear what caused the fire that led to this opulent hotel's demise.

Home to fantastic views and ancient graves.

South of Bologna, a limestone grotto with a protruding waterfall and a floor full of cave pearls.

Sitting on an Italian hilltop is this surreal fortress built by the mad inventor of electrohomeopathy.

A glimpse at Walt Disney's vision for a "community of tomorrow," in miniature.

Amid skyscrapers and traffic exists this unique aquatic ecosystem.

This sign designates the road that leads to the infamous Area 51.

The grounds and buildings of an old wood pulp mill have been transformed into an innovative art park and museum.

A stately castle in the northern Italian countryside has been restored after years of neglect.

A striking 12th-century-style castle built on the edge of a cliff.

An impressive bridge over a ravine also served as an aqueduct.

This hiking/biking/horse trail along an old railroad grade features trestles, tunnels, and a roadless stretch through the scenic Susan River canyon.

The tallest bridge in California was constructed for a project that was eventually cancelled.

Amazing views of Long Island Sound can be seen from this mountaintop tower.

A sun-filled museum featuring an ever-rotating collection of classic and exotic cars.

A remarkably futuristic building sits in the oldest town in Louisiana.

A road that winds through this natural cave is the only way to access the small, appropriately-named village of Cuevas.

Located inside a former bread factory, this museum explores a century of transportation history through innovations that were extraordinary or failures—sometimes both.

Rushing water plunges over a 100-foot drop created by an ancient lava flow at this majestic waterfall.

This striking arch, one of the first architectural elements constructed in Prospect Park, was recently restored to its original glory.

This peculiar Italian elevator runs both horizontally and vertically.