Hidden beneath the streets of London is a secret subway that only carried mail.

Part modern art project, part traditional chapel, this see-through church is only substantial from the right angle.

Cold storage for agricultural biodiversity.

This abandoned mining village was predicted to resist decay longer than any other modern human settlement.

This homeless brass fox tugs at your heartstrings from the foot of a Stockholm bridge.

The world's most delightful not-NOT-religion welcomes visitors to the town of Templin, just like its more stoic peers.

A maze of crosses marks the jumbled divide between the Netherlands and Belgium.

The world's only museum devoted to the wonders of fluorescence.

Grotto replete with mystical designs laid out in glued shell mosaics.

An eerie, derelict amusement park in Berlin.

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

The mysterious, fantastical woodland inspiration for "The Lord of the Rings."

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

This massive underground salt mine now holds a sci-fi theme park in its depths.

Giant, friendly pelicans in Central London, the most unlikely of places.