A war-torn Olympic relic is being overtaken by graffiti and nature.

This abandoned Olympic skiing facility still bears the scars of the Siege of Sarajevo.

The world's most famous donkey lives in this pen.

Legends of treasure and spirits flow from this this fairy tale-like oasis.

This old train trestle and collapsed tunnel once allowed the railroad to negotiate the steep slopes of the Colorado Rockies.

This hunter-gatherer architecture is believed to be the oldest religious complex known.

A mysterious light floating in the trees of Arkansas may be a piezoelectric effect.

A mysterious light of unknown origin on the backroads of Missouri.

One of America's first dinosaur parks gives a window into Depression-era paleontology.

This is one really big nut.

A hand-built folk art installation covered with messages of God's love.

The frozen bubbles that form on the icy surface of this Canadian lake contain enough methane to create a small explosion.

An experimental, automotive replica of Stonehenge.

An abandoned Jazz Age dream home and con man's hideout in Death Valley.

Buenos Aires' city of the dead contains some very famous remains, including Eva Perón.

This scalding hot river was thought to be a myth until one geoscientist made it his quest to study the mystical waters.

The "Fun Spot of the Desert" is now a haunting ruin, and a reminder that putting a water park in a desert is a bad idea.

One man's ambition created this psychedelic log home.

In this historic region, homes and churches are carved into ancient volcanic rock formations.

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

A fiery crater has been burning in the Karakum Desert since 1971.

A notoriously corrupt Chief of Police's deteriorating Greek-themed playhouse.

Known as the site of 'El Dorado,' this mysterious lake is rumored to hold gold beneath its waters.

Ruins of a Carnegie family mansion on Cumberland Island.