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

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

An intriguing three-sided folly is a testament to one man's devotion to Catholicism and the number three.

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

Unusual British home built to disguise a water tower.

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

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

Scotland's oldest medieval bridge is also among the last reminders of early medieval Aberdeen.

Mysteriously stacked storefront paths give this medieval British town an iconic style like none other.

The whimsical twist of this spire was either caused by the Devil, an unexpected virgin, or lead.

This abandoned oil depot produces world's longest echo in a manmade structure.