Surreal riveted sea forts once protected the Kent shores from German attack.

The world's first underground farm is in a World War II bomb shelter beneath the streets of London.

The site of London's first coffee house has been serving refreshments of one kind or another for 360 years.

Eighty million natural history specimens call this gargantuan museum home.

This series of Scottish caves has no clear purpose other than baffling historians.

A historic house left in "dramatic still life."

Catacombs turned marketplace.

In this cobwebbed old operating theater, you can practically hear the screams of the unanesthetized patients.

A island reachable by a causeway at low tide is possibly one of the earliest Western European locations to be identified in text.

Hear the quietest sound from across the dome.

A fantastic castle rumored to be the birthplace of King Arthur.

Several plaster noses are hidden in plain sight around London's Soho neighborhood.

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

A 1,215-foot tunnel transports pedestrians beneath the River Thames.

Rebuilt remains of a temple to Roman god Mithras.

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

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

A student driver's nightmare.

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

The only university zoological museum in London houses extinct animals, bizarre natural history specimens, and a Micrarium of microscopic creatures.

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

An unusual round church in London with a Templar past.

The longest hedge maze in the world.

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