The hellish conditions of this abandoned mine that snakes beneath the Pacific Ocean gave it its diabolic name.

Ernest Hemingway was the first to sign this colorful wall covered in thousands of celebrity signatures.

The graveyard holding the remains of George Washington's slaves was forgotten for nearly 200 years.

Hidden in plain sight on the Hudson River is an abandoned train station where nature has taken over.

Now abandoned, the first public health hospital in the U.S. saw more than one million immigrants from around the world.

A midcentury ranch house hides a literal treasure trove of unique rocks and minerals.

The largest wooden building in the world now houses a fascinating collection of aircraft.

Its vintage camera collection gives a snapshot of the past as viewed through a photographic lens.

Endless rows of boxes of paper records line the hallways of the archaic federal facility where guns are traced.

Strange, gentle beasts resembling goat-cow hybrids roam within this patch of forest.

Western Europe's only representation of a Roman goddess still in its original location sits in an unassuming park.

Iceland's only steampunk shop imagines a retro-futuristic world that never was.

This remote research station sits amid the second-largest ice sheet on the planet.

One of the largest collections of socialist realist art shows the surprising depth of the official art of the Soviet Union.

This gnarled old tree supposedly sprouted from seeds kept in the pocket of a 16th-century Spanish sailor.

This gorgeous reading room houses the oldest and largest art history library in the Netherlands.

A locomotive that was captured as a prisoner of war is now recognized as a WWII memorial.

A 300-foot-long Cold War submarine floats in a Chilean River as a maritime museum.

The steepest classic funicular in the world glides along a dizzying incline.

The now-abandoned tunnels were built for the transcontinental railroad on the route where the first wagon train entered California.

This little blue house pokes out over the campus of UC San Diego, seven stories high.

The 10-foot-wide Long Beach home was built on a dare.

The main gates have been locked since 1745 and will remain so until the Stuart Dynasty returns to the throne.

The 16th-century church has the only stained glass windows that survived the Scottish Reformation intact.