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

A hermit's tiny cell built into the cliffside that saved him in South Pembrokeshire.

Formerly abandoned underground complex to keep royals safe from a nuclear war that never came.

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

Two plaques commemorate the site of Shakespeare's first theatre.

Follow the original medieval paths that wind through this intriguing section of the city.

This waterfall is one of the most spectacular natural features in the Scottish Lowlands.

Western Europe's only representation of a Roman goddess still in its original location sits in an unassuming park.

This cramped crevasse saw the entire population of its island suffocated inside its depths.

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

Dating back almost 400 years, the oldest public collection library in the United Kingdom was once the study hall of Karl Marx.

This abandoned asylum in Wales might look haunted, but it's still beautiful.

Museum about life, death, and cannibalism in the Stone Age.

Created hundreds of years ago, the magical follies and landscapes at this park were almost lost to time before being restored.

The one-time stronghold of the noble Douglas family, now home to ghost sightings and nesting birds.

A Victorian Gothic masterpiece housing a world-class collection of rare books and manuscripts.

It is said the legendary wizard once lived in this sea cave beneath Tintagel Castle.

An American ghost town hides along a side street in Scotland's capital.

A site of pagan worship which still attracts people looking for fairies.

This allegedly haunted 16th-century tower house-turned-museum exhibits thousands of spectacular objects.

This medieval sanctuary's tree-framed door looks like a portal to a mythical realm.

The largest cave chamber in Britain—big enough to fit a whole cathedral inside.

Come for the oysters, stay for the priceless art honoring inventors across history and Scotland's favorite outdoor sports.

This iconic 1,000-year-old medieval castle is a favorite of the film industry, most notably as the location for Hogwarts in Harry Potter.