A self-built castle made by a mysterious man.

An 80-year-old house built out of newspapers.

A lake with hundreds of ancient skeletons surrounding it. The surprise is what killed them.

The Arctic Archipelago is home to world's largest third order island: an island in a lake on an island in a lake on an island.

An obscure public service from the U.S. government that redeems burnt, moldy, and soiled old greenbacks.

New fungal and bacterial species call this deadly lake home.

The once forbidden "secret cabinet" of erotic art from excavations of Pompeii and Herculaneum.

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

The hidden "ballroom" under a mansion lake was built by a criminal who ate a cyanide pill during his trial.

Yale University's home for rare works, including the mysterious Voynich Manuscript.

While many places make the claim, the Library of Congress says this restaurant is the birthplace of the hamburger.

An archival collection of over 2,200 case studies which includes human brain specimens and tumor specimens.

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

Three connected pink triangles memorialize persecuted gays and lesbians throughout history.

This secret cemetery where no flag is allowed to fly holds the bodies of American soldiers convicted of heinous crimes during WWII.

Colorful and chaotic stacked hotel in North Holland.

The first museum in the world devoted to sexual gadgetry.

An eatery in a shallow river where diners can enjoy their meal mere feet from the base of an artificial waterfall.

The famous winding walk at Chartres is surrounded in mystery and myth.

This giant middle finger statue sends an unambiguous message to Italy's bankers.

The ruins of an ancient island city built atop a coral reef in the South Pacific are spectacular and strange enough to have inspired H.P. Lovecraft.

Twice a year, visitors can tour the desolate site that birthed the Atomic Age.

A curious collection dedicated to human and animal anatomy and pathology.

A nightly tradition fills the streets of Flogsta with a collective scream.