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

This floating garden in the sky is straight out of a fairy tale, but the real thing is nothing short of magical.

A modest stone circle in North Wales.

A 4,500-year-old forest is slowly being revealed from beneath the sands of a Welsh beach.

The lake that fills and empties itself at random.

The remains of centuries of copper mining appear like an alien landscape.

Northern Ireland's Brobdingnagian stepping stones.

The atmospheric road was never meant to be so creepy.

A massive Celtic cross secretly growing in an Irish forest.

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

A museum that cashes in on its infamous little people while teaching you a thing or two about the Irish fey.

This ancient Irish tower could easily have stood in for Rapunzel's prison.

A standing relief of a Norman knight whose posture marks him as a Crusader.

An outstanding and haunting glimpse of the horrors of the Great Famine of Ireland.

A collection of housewares from recent Irish history adjoined by a tower from ancient Irish history.

This burial pyramid in central Ireland is thousands of miles and thousands of years away from its Egyptian inspiration.

These fantastically named natural pools look like something out of a Scottish myth.

Possibly the oldest of Britain's ancient henges is also one of its most stark.

A whale's jawbone and a malfunctioning harpoon welcome you to the village of Bragar and its lore.

Small Island off the coast of Greenland.

Despite finally receiving electricity in 1970, this tiny town is now deserted.

This remote island village was in danger of depopulating completely until a tunnel was built to connect it to the rest of the world .

A "simple-hearted artist" turned an isolated Icelandic valley into his own art museum.

This modern monument to pagan belief looks like it was transported straight from ancient times.