Now harmless, this looming post struck fear into the heart of medieval troublemakers.

When a supermarket opened up shop within a medieval building it became protected by UNESCO on a technicality.

This former estate of a fascist leader is now a burnt out ruin leading to a system of secret tunnels.

Yugoslavia's biggest underground airport lies in ruins.

A musical instrument played by the sea.

A chain of 16 wondrous lakes formed as a result of the gradual dissolution of soluble layers of bedrock.

Fortune tellers, snake charmers, poets, and storytellers all gather on this historic square in Morocco.

There was a top secret plan during World War II to seal a group of soldiers inside the rock.

Hauled from the water's depths, Henry VIII's flagship is preserved in this capsule-shaped museum.

This striking observation tower shaped like a spinnaker sail is the newest icon in historic Portsmouth.

A miniature village mimics the surrounding buildings so well it includes itself.

A lush indoor jungle fills this bustling Madrid transportation hub.

The Great Fire of London and the regulation of one-way streets both started in this alley.

The commemorative stone column conceals a secret laboratory.

One of the few remaining casualties of the London Blitz, this destroyed church has become an enchanting public garden.

An alleyway plaque is all that remains of the independent Texas' envoy that forgot to pay their rent for over a century.

Single runway interrupted by a busy road that cuts across its middle.

The sign at the garden gate reads: “These Plants Can Kill.”

This enormous secondhand bookstore inside a Victorian train station sparked the "Keep Calm and Carry On" craze.

The largest timber structure in Europe.

These lamps were created to expel sewer gases after an event known as The Great Stink.

A rather grand, but tiny, folly on the banks of the River Wear associated with a Polish count.

These upturned herring boats make nifty storage sheds for fishing goods.

Twice a day this ancient path disappears with the tides, leaving the Holy Island of Lindisfarne out to sea.