The oldest working mechanical clock in the world.

Huge concrete structures designed as an early warning system for Britain to detect enemy aircraft.

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

Largest lake in Great Britain measured by surface area.

The remains of Crystal Palace Great Exhibition of 1851.

Gothic tower mentioned in Thomas Hardy poem "The Channel Firing."

Below a historic English market town lies a secret underground city complete with kitchens, laundries, storerooms, and an underground lake.

Old-fashioned knowledge and modern engineering create the world's only rotating boatlift.

A 550-square-meter micro-nation off the coast of Britain.

The breadfruit-adorned final resting place of the infamous Captain of the HMS Bounty.

This one has sailed five times as far as Sir Francis Drake's famous ship.

Rebuilt remains of a temple to Roman god Mithras.

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

London's smallest police station is barely the size of a phone booth.

Charles Babbage's proto-computer, painstakingly brought to life.

Hear the quietest sound from across the dome.

Bronze sculpture celebrating the relationship between Churchill and Roosevelt.

A historic arboretum and non-conformist, non-denominational park cemetery.

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

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

A clock designed to run with perfect accuracy for 10,000 years.

Three bridges straddle a stream, one stacked upon the other.

Used as an example in one of the first dictionary entries for "museum" in 1706.

The beams of the New College, Oxford dining hall come with an amazing story.