On Gellért Hill, this statue depicts the tragic tale of lovers divided by the Danube.

A small etching on the white marble parapet was written in runic script by a Viking mercenary.

This fancifully decorated Victorian home in New York’s Hudson Valley is the only known fully domed octagonal residence in the United States.

The only swimming pool listed on the National Register of Historic Places is emptied and refilled each day with naturally filtered water.

Located more than 600 feet beneath sea level, this tunnel boasts the world's first undersea roundabout.

A monument to the legacy of the man who created Spongebob Squarepants at the school where his passion for art and marine biology began.

What might be the oldest living tree in London has survived fires, bombings, and estate agents.

More gold than anywhere else, ever.

The camera-toting gargoyle juts out from the exterior of a Gothic cathedral.

A cemetery in Barcelona's Poblenou district is home to this touching funerary statue, which depicts death in the form of a winged skeleton.

This site in Caldwell County is the location where the Cherokee and Catawba are said to have entered a peace treaty.

This dreamlike museum is filled with the works of an influential surrealist artist whose name you may have never heard.

The absurd creation is a compulsory destination for selfies in Buffalo.

An acoustic anomaly with a mysterious cause.

These pillars are one of the few remnants from the mysterious lost empire of Makuria.

There's a 12-foot-tall replica of the Washington Monument hidden under a manhole nearby.

This imprint of an old computer keyboard has a unique backstory.

A historic presidential getaway on the continental United States' southernmost island.

These remote Florida islands have a history of sea turtles and sunken treasures, and one of the world's largest coastal brick fortresses.

A stack of stones steeped in Irish folklore, much like the hero they're connected to, hide in plain sight.

Of all the unique artifacts inside this library, a mummified hand stands out among the others.

A taste of Middle Earth, in the middle of the Bayou City.

The only residents of this abandoned housing development full of identical castles are stray cats and dogs.

The largest lake in the Faroe Islands seems to be held hundreds of feet above sea level thanks to an optical illusion.