Artworks by loners, prisoners and the criminally insane.

A trove of ridiculously valuable prints and manuscripts under one roof.

Where Mary Shelley’s "Frankenstein" and John William Polidori's "The Vampyre" were born.

A rare, flower-shaped example of Brutalist architecture in Switzerland.

The ruins stand as a somber reminder of France’s worst civil catastrophe of the 20th century.

A nearly 500-year-old sculpture depicts a man eating a sack of babies, and no one is sure why.

This secluded walkway overlooks a magnificently wild London green space.

The remains of Crystal Palace Great Exhibition of 1851.

A kaleidoscopic warehouse-maze of handmade neon signs.

This historic stone bridge has an entire neighborhood clinging to its sides.

Beloved children's TV characters freckle the German city's streets.

An ordinary lamppost situated in the middle of Cambridge has an unusual moniker and history.

The ancient mosaics here are considered among the finest in the world, and serve as a stunning record of Greco-Roman daily life.

This famous writer's tombstone is a literary pilgrimage site that was publicly defiled by a rival.

Vines grow up the metal bars in this public park created from an old machine factory.

Nestled in the heart of Milan is a real wunderkammer of morbid curiosities.

The beloved fantasy novelist is buried near a church containing a whimsical etched glass window full of Narnia favorites.

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

The sign at the garden gate reads: "These Plants Can Kill."

La Monte Young and Marian Zazeela's "Dream House" will immerse you in an ever changing world of sound and light.

This astonishingly geometric cave has inspired everyone from Jules Verne to Pink Floyd.

Hidden in the shadow of a rocky fortress is one concubine’s long-forgotten legacy.

A clock designed to run with perfect accuracy for 10,000 years.

Hidden behind a wall for decades, this masonic lodge was only rediscovered during renovations.