Islanders once used this dramatic, otherworldly landscape to hide their cattle from Viking raiders.

Shakespeare, David Bowie, Dr. Who, the Saxons, Druids and Romans are all claimed to have all made their mark on these massive man made tunnels.

A subterranean playground in an abandoned slate mine.

Remnants of a Victorian garden feature sitting in public woodland.

This castle was established by the 4th Duke of Montrose and is connected to the Buchanan Clan.

Rebuilt remains of a temple to Roman god Mithras.

A tongue-in-cheek arcade where the games are based on everyday life.

A 30-acre garden inspired by the principles of modern physics.

This collection of illusory paraphernalia has been culled from the history of London's premier magician's club.

This dramatic landscape hidden on the Isle of Skye looks as though you've stepped into the magical realm.

This shop and gallery is a modern-day cabinet of curiosities, unassumingly positioned along an urban thoroughfare.

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

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

The effect of this ancient form of image projection situated atop an 11th century Moorish palace is thrilling.

The Bristol Camera Obscura housed in an ancient windmill.

360° views of the city plus five floors of optical illusions and hands-on science.

An optical Illusion once believed to be an electrical phenomenon.

This small Estonian hill is covered in hand-made twig crosses that are said to bring good luck.

Paris' linguistic guide to the international language of, yes, love.

Stockholm's decidedly unique public transit system has doubled as the world's longest art gallery for decades.

An Amsterdam street lined with antique shops each one dedicated to a different obscure collection.

An eccentric artist's abode in this small Italian town has been transformed into a surreal temple of mosaic madness.

A 125-meter long "tribute to the Brazilian people."

Mosaics created from 11 million cigar bands.