An imperial church bombed to ruins during WWII now stands as a jagged memorial.

Terrifying derelict military hospital once housed a recuperating Hitler.

These former Nazi anti-aircraft towers offer a singular view of the north of Berlin in the summer, and a sanctuary for bats in winter.

A tour of underground Berlin takes you through WWII air raid shelters and tunnels used to smuggle people out of East Germany.

An eerie, derelict amusement park in Berlin.

Started as a kitchen garden, now the second largest botanical garden in the world.

The fairy tale castle of the "fairy-tale king."

This freshwater spring fills with 10,000 gallons of water per minute.

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

One man's dream has turned into this naturally growing chapel made of almost nothing but trees.

Not for the faint of heart, this long pedestrian bridge rewards those who brave the wobbly walk with a beautiful view.

To get to or from this Canadian ghost town, you'll need to cross 11 single-lane bridges.

The longest navigable underground river in the United States is home to countless blind and albino animals.

A stunning, abandoned limestone quarry in southern Indiana provided the stone to erect the Empire State Building.

A glimpse of a waterfall is reached by a steel catwalk along a slot canyon located in an Ouray city park.

A dangerous narrow-gauge railroad once traced a route through this striking canyon.

A long and winding trail through history led to the current iteration of this mountaintop tower.

The narrow mountain road that carves a path between Florence and Victor is tied to ghost towns and ghost stories.

Thanks to a quirk of elevation this gift shop produces magic doughnuts that are found nowhere else on Earth.

The largest self-built castle in the U.S., six decades in the making.

Wondrous sandstone hoodoos where Native Americans collected clay for pottery, 9,000 years ago.

This super steep hike ascends 2,000 feet in less than a mile.

This spectacular track has run continuously since 1882.

These decaying bridges 1,000 feet high are a reminder of the skill it took to cross the Colorado Rockies by rail.