An unusual round church in London with a Templar past.

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

Microscopic fossils suggest Australia may be the birthplace of sulphur-based life forms.

A nearly unconquerable island-fort in the Indian Ocean.

Home on the Hillside, and home of the first breakfast cereal.

A little lighthouse in New York City, surrounded by mysterious stories of insanity-driven construction.

A former insane asylum despised by Nelly Bly and Charles Dickens is now fashionable apartments.

A crumbling hospital from the 1850s on Roosevelt Island.

Site of the first pathological and bacteriological research facility in the United States.

A dangling church built over a Colombian gorge.

King Ludwig I's collection of beautiful women.

A small but immensely extravagant palace built by the "Night King."

The fairy tale castle of the "fairy-tale king."

This immaculate and historic water garden culminates in a massive stone dining table with an inset fountain for chilling the wine of the Cardinal's guests.

Cretean quarry suggests real-life site for ancient Greek myth of the man-eating Minotaur in his labyrinth.

The mountaintop inspiration for Umberto Eco's "The Name of the Rose."

WWI hospital ship lost in a cyclone turns up on the coast of Fraser Island, where she remains rusted and forgotten.

A Belgian self-built tower inspired by the Bible and ancient civilizations.

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

Iron Age grave stones and Viking burials, a short drive from Gothenburg.

Housing a morgue, rare and confiscated weapons, and autopsy remains, the Vancouver police museum displays the dark side of Canada.

Home inspired by the crystal rock formation of the Emerald Estates.

Low tide reveals 8,000-year-old rock carvings in Southern Alaska.

Burial site more than 300 years old.