Glasgow’s piece of the patron saint of love.

The skull of the patron saint of lovers lies in the Basilica di Santa Maria in Cosmedin—maybe.

A huge musical instrument played by the ocean.

Bring your own cardboard to the slippery slopes of concrete hidden in a neighborhood park.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

A beautiful but toxic fountain of mercury.

Gaze upon chocolate sculptures depicting everything from chariot races to Gaudí's famous church at this shrine to sweets.

This cemetery features modernist statues as strange as its name.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

This antique thermometer honors the creator of the first universal temperature scale.

The relics are stored in a silver reliquary, where they can be seen through glass.

Books you don’t need in a place you can’t find.

This former Masonic hall has been turned into an art project that uses even more metaphysical iconography.

A beautiful Victorian-era cemetery, complete with a miniature village.

This Boston medical museum features the skull of the famous medical case of Phineas Gage.

A unique seaside cave where Aleister Crowley faked his own death.

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

The hallucinogenic center of the ancient world.

Northern Ireland's Brobdingnagian stepping stones.

Perfectly preserved ancient monastery in an impossibly dramatic location on a rocky island in the Atlantic.

One of Ireland's most infamous prisons for rebels including men, women and children.

Obelisks and stone pineapples in the Irish countryside.

An exquisite panometer representing Dresden as it was from 1695 to 1760.

To the great disappointment of doomsdayers, this codex merely contains records of the Moon and Venus.