No one is sure what to do with this WWII shipwreck that sits at the bottom of the Thames, still loaded with tons of explosives.

This abandoned gun tower was built to defend the River Thames from a French naval attack.

Overlooking the seaside town of Margate stands a tribute to an artist's lover.

A beautiful Kentish country intersection hosts a tasty little photo spot.

This curious Tudor-era castle was once home to Napoleon's greatest adversary, the Duke of Wellington.

One of the few standing Roman lighthouses and a labyrinth of tunnels are a couple of the secrets at this historic castle.

A house of bones — but nobody is quite sure to whom they belong.

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

The Neolithic megalith was one of the first archaeological ruins protected by the British government.

A Neolithic burial site built 1,000 years before Stonehenge.

Horsemen once used this tilting post during jousting practice.

This star-shaped artillery fort protected the mouth of the Thames from the 16th century to the Second World War.

A lush indoor jungle fills this bustling Madrid transportation hub.

Madrid's romantically ornate crystal palace has been offering shelter to plants and art for over a century.

Napoleon's childhood home is now open for people to explore the beginnings of France's short general.

This narrow fjord-like bay is the largest ria in the Mediterranean Sea.

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

A wonderfully strange collection of 500+ stuffed frogs doing people things.

The big toe of this towering monument to a Croatian national hero is worn from years of superstitious rubbing.

The sole surviving medieval street cross in Scarborough.

Believed to be the longest railway bench in the world.

These grandstands are among the oldest continuously used stands in the world.