Rebuilt remains of a temple to Roman god Mithras.

A special shop catering to the needs of things that go bump in the night, and also helps kids become writers.

A vast overgrown cemetery, once known as one of London's "Magnificent Seven."

The largest of London's subterranean rivers and once a mad, bad center of London life.

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

A subterranean ice warehouse that has lain hidden beneath central London for over a century is now open to the public.

Amazing and mysterious Neolithic settlement on Scotland's Orkney Islands.

Wedged between two buildings at the Great Ormond Street Hospital is this secret music installation.

A student driver's nightmare.

Ruined 11th century abbey built by King David I in Edinburgh, Scotland.

Banksy gives themself artistic license with this piece of London street art.

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

An unusual round church in London with a Templar past.

A hands-off space for graffiti artists to hone and display their skills.

The longest hedge maze in the world.

Winding paths and ramshackle mausoleums in the oldest "park cemetery" in London.

The most iconic structure in Scotland has been home to bishops, colonels, and Sean Connery characters.

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

17th century streets hidden under Edinburgh were once a breeding ground for the black death.

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

Northern Ireland's Brobdingnagian stepping stones.

This South London cemetery holds the remains of more than 15,000 people.

The atmospheric road was never meant to be so creepy.

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