Some of England's last cave dwellers lived and worked within this huge cave.

Besieged by war, this castle ruin has crumbled into a peaceful picnic spot.

The longest hedge maze in the world.

An enormous steel waterfall is a nod to the substance that shaped Britain's Steel City.

Cemetery established by the Victorians as a solution to the overflowing graveyards.

This Norman castle has been the scene of assassination plots, religious persecution, and Nazi conspiracies throughout its long history.

With lush plants and flowers, huge trees, ponds, and hidden monuments, this place feels a bit like discovering Narnia.

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

This mysterious hilltop collection of Druid carvings isn't quite what it seems.

A 200-year-old prison that now houses a peculiar crime museum.

The world's first successful water-powered cotton mill paved the way for the factories of the British Industrial Revolution.

Near Birmingham, England three and a half miles of top-secret tunnels housed a World War II “shadow factory” and a Cold War nuclear bunker.

This foolish Victorian sea fort was converted to a deluxe hotel.

In the U.K., a historic workhouse shines a light on the early, harsh treatment of the poor.

Quaint, disturbing, and macabre objects are all on display at this intriguing collection of medical instruments from bygone eras.

This unchanged Victorian park is rumored to have been the inspiration behind Peter Pan's Neverland.

A chaotic collection of coin-operated slot machines designed to delight and disturb in equal measure.

This historic abandoned train station looks like a stop for ghost trains.

Colin Stokes "got a bit carried away" and built a castle that looks like something out of Tolkien.

This colossal war machine is now a living museum dedicated to underwater warfare.

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

It's possible to walk inside one of the largest Neolithic tombs in Britain.

This medieval manor house was equipped with secret compartments for hiding priests.

One of the largest sculpture collections in the U.K. features history's greats, from Bob Dylan to Galileo, in bronze.