The undercroft is a spectacular example of medieval Cistercian architecture.

A memorial to American oil drillers who volunteered to travel secretly to England in 1943 and work in the U.K.'s only oil field.

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

A little-known ruin with a convoluted history and a fascinating latrine drainage system.

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

A 15th-century house single-handedly disassembled then reassembled bit by bit 100 miles away.

Britain’s highest medieval monastery is a remote ruin nestled at the head of a valley 1,240 feet above the sea.

There's a strange stone hoodoo towering atop a wooded hillside and no one is quite sure how it got there.

England's only square-dimension hill horse was built to celebrate Queen Victoria's coronation.

These Roman ruins in England’s Lake District are 2,000 years old, but look pretty good for their age.

This ruined 15th-century hermitage is steeped in myth and mystery.

This ruined folly was originally built to honor a failed American state that would have become "Westsylvania."

After years of slow decline, a derelict Gothic castle is now being restored to life.

The weathered grave of a medieval anchoress who walled herself up in a cell attached to a church.

The centuries-old obelisk may have inspired J. R. R. Tolkien.

This oak sculpture at the edge of a small woodland is nine feet tall and shrouded in mystery.

This overgrown Victorian chapel made of corrugated metal looks utterly out of place.

A unique 1980s designed church sits uncomfortably in its traditional Victorian churchyard.

This World War II airfield is the last place the bandleader performed before he disappeared.

The collapse of the brand-new dam caused one of the worst floods in British history.

Local legend says this unusual chimney is actually a broken-hearted man's tomb.

The world's first military tank was designed in this English city amid the stalemate of WWI trench warfare.

The remains of a historic kiln once used to produce the famous Rockingham porcelain.

The historic site where Queen Elizabeth I once gave a searing speech.