An open air haven for tropical monkeys in the damp moors of the English country.

A relic of Victorian grandeur hides beneath a busy South London road.

Tucked away in the Tower of London is the weapon once used to execute high-profile prisoners.

What happened to the three lighthouse keepers who vanished from this place remains a mystery over a century later.

The abandoned funicular tunnel was a secret base for the BBC during World War II.

This charming railway is one of the oldest and steepest funiculars in England.

A spiral staircase connects the limestone cave with Pembroke Castle, birthplace of King Henry VII.

This former abandoned hospital, a complex of stunning 19th century buildings, once housed 2,000 psychiatric patients.

This long-hidden space above Westminster Abbey now displays the battle gear of the legendary King Henry V.

Under a church hides a forgotten 13th-century ossuary containing the remains of around 2,500 people.

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

19th century tunnels burrowed under Liverpool.

This skewed English house has looked like it's going to fall over for centuries.

This lonely cast-iron structure is the only wave-washed lighthouse of its kind left in all of Britain.

A beautiful ruin of a 14th-century Plantagenet castle built by a medieval mercenary.

Sometimes an island, sometimes a rocky outcropping connected to the world by a tiny suspension bridge.

The beloved fantasy novelist is buried near a church containing a whimsical etched glass window full of Narnia favorites.

The ruins of this medieval castle in Northern Ireland have inspired artists from C.S. Lewis to Led Zeppelin.

Overlooked by many, the two famous Scottish warriors guard the main gate of Edinburgh Castle.

The watery entrance for condemned prisoners heading to the Tower of London is still visible along the Thames.

Human-made caves excavated to hide a secret society of wealthy pagans.

Richard III supposedly disposed of his nephews' bodies here in an effort to seal his claim to the throne.

Monty Python fans will recognize this abandoned mine as the Cave of the Killer Rabbit of Caerbannog.

This romantic, decaying 13th-century ruin on the edge of Sherwood Forest is reputedly one of England's most haunted places.