A remarkable medieval structure born from a 14th-century disaster.

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

A petite castle folly in the English countryside.

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

The abandoned transportation hub hides within the Glasgow attraction it once served.

This century-old grotesque has a mysterious history and may not actually be a rabbit.

This picturesque archeological site looks like it was pulled straight from a fantasy novel.

These ruins witnessed the final gathering of the failed Jacobite Rebellion.

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

This Gothic Revival castle used as a shooting location for "The Secret Garden" and other films.

A harem-inspired Moorish fantasy design in a Victorian-era Welsh castle.

These stark white cliffs were spat up by the sea and are slowly being retaken by it.

The stately remains of Llywelyn the Great's mighty fortress.

England's most notorious suicide spot.

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

The ruins of an 11th-century Norman castle with a rare, perfectly circular shape.

Three bridges straddle a stream, one stacked upon the other.

This well-preserved Cistercian Abbey in a romantic pastoral setting has inspired artists like the poet Wordsworth.

This modern labyrinth lies in the shadow of a ruined medieval castle.

One of the oldest and certainly best preserved Cistercian abbeys still in existence.

The taxidermy remains of the first mammal ever cloned from an adult cell are on display in Edinburgh.

A familiar otherworldly creature guards this 12th-century Scottish abbey.

The names Lúthien and Beren can be found inscribed on the shared grave of the famous writer and his beloved wife and muse.

Large-scale contemporary artworks tower over fields and lurk in forests around a Jacobean manor house.