The world's only three-story rotary jail is now a museum to a bizarre trend in prison design.

Franciscan monks created a facsimile of the Holy Land for North Americans who couldn’t afford the trip overseas.

The final resting place of the poets Shelley and Keats.

The royal seat of Henri Christophe, a formerly enslaved man who became Haiti's only king.

The Gaudí-inspired building that was the start of Terrassenc modernism.

An abandoned convention space that has been left to the homeless and the radical.

The stones of this Incan wall complex fit together so well you couldn't fit a piece of paper between some of them.

Strange rock formations tower above the river that snakes through this enchanting Icelandic canyon.

The body of St. John Neumann and his collection of hundreds of relics, on display in a Philly church.

Fortified medieval tower house with lovely roof garden.

A 14th century bridge built as a fortress, where the devil lurks on one of its towers.

Cursed swimming pool left abandoned is now a favorite of filmmakers and ghost hunters.

A line of abandoned, alien-like fortresses dot the mountains of North Italy.

Once America’s most beautiful army base, this abandoned military fort on the coast of Monterey Bay has been left to the elements.

Large, airy hallways hide within an impenetrable fortress that beckons urban explorers.

The site of one of Japan's very few American occupations during World War II still holds the relics of a roundly disastrous campaign.

A man-made island designed to look like a massive battleship.

The names Lúthien and Beren can be found inscribed on the shared grave of the famous writer and his beloved wife and muse.

J.R.R Tolkien, C.S. Lewis, and other "Inklings" met at the Oxford pub to discuss the now legendary fantasy stories they were writing.

The haunting ruins of a military fortress turned astronomical observatory sit on a Sarajevo mountaintop.

Amid the bustle and noise of the Financial District hides a secluded garden oasis above the city streets.

Beautiful Victorian buildings from L.A.'s forgotten architectural past.

A railroad tunnel that, upon its completion, was considered one of the engineering marvels of the modern world.

The only recreation of William Shakespeare's indoor playhouse.