Once the world's largest reinforced concrete structure, this abandoned bridge now beckons urban explorers.

This road in the Great Smoky Mountains was supposed to assuage a displaced community, but ended up a $52 million dead end.

Whimsical artist house in the New Jersey woods.

One of the U.S. Forest Service's only mansions is outfitted with a dinner table for floating food.

Tucked behind New Jersey's abandoned Gingerbread Castle lie the eerie ruins of a once-flourishing paper mill.

Hundreds of glow-in-the-dark objects light up a museum in a historic zinc mine.

A train station that was abandoned by the coal industry and was later converted into a cocktail bar.

The graffitied ruins stand hidden within the Pennsylvania woods.

Six peaceful acres in a residential neighborhood dedicated to art and peace.

This concrete tangle of square pipes has stood as a proud thorn in the city's side since the '70s.

A breathtaking bridge that crosses a vast gorge over a river's torrents, and has a tale of a devil architect attached.

Three wildly colorful calderas top this otherworldly volcano chain.

Ain't no party like a ghost town party.

Founded as a refugee camp, now a popular tourist spot.

Mosaics, storks, and brothels—this ancient city has it all.

Unique geological formations in China, featuring some suggestive shapes.

This unusually shaped mountaintop tower looks like a UFO floating over the city.