A 13th-century stronghold that has fallen into ruin.

One of the best-preserved, yet least visited stone circle sites in Cumbria.

Local legends say that fairies used to dance in the moonlight here and invite handsome young men into their grottoes.

It's believed a local adventurer spent 50 years living inside this cave.

Each spring this woodland floor is carpeted with purplish flowers as far as the eye can see.

19th century tunnels burrowed under Liverpool.

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

This triumphal arch celebrating the Sun King's conquest of Lille is a masterpiece of military architecture.

The site of the first medieval crusade that pitted Christians against Christians.

A sublime medieval path adorns the marble floor of one of the most beautiful Gothic cathedrals in France.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

A Neolithic tomb hidden among a spectacular boulder-strewn stretch of coast.

The artist David Nash planted a circle of trees in 1977.

Quirky Welsh observatory unites art and science.

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

A former fisherman's hut deemed too small for habitation is now a delightful tourist draw.

The world's largest prehistoric copper mine had 30,000 animal bones scattered throughout the maze of passageways.

A wildlife paradise, this island is one of the world’s most important habitats for burrow nesting seabirds.

The remains of centuries of copper mining appear like an alien landscape.

This Roman amphitheater is said to be King Arthur's legendary Round Table.

Picturesque ruins once held off mighty armies.

These haunting ruins belong to an ancient village that once had one hell of a view.

One family's environment-friendly hobbit-house in Wales.

High Victorian fantasy created a fairytale castle out of a ruined fortress in Wales.