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

Ancient Bronze Age rampart that was used into the middle ages.

The ancient tomb acts as a calendar that keeps perfect time.

A rocky sea serpent hides caves, blowholes, and a spectacular natural bridge.

Obelisks and stone pineapples in the Irish countryside.

Quirky Welsh observatory unites art and science.

A corkscrew-shaped barn in Ireland.

One of Ireland's most infamous prisons for rebels including men, women and children.

An Irish church where an 800-year-old mummy is reaching out of his coffin as if to shake hands.

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

Rare collection of medieval books under lock and key.

The largest known medieval map of the world.

World's largest working waterwheel has been around for over 150 years.

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

A modest stone circle in North Wales.

Astonishing rock formations dot the Brimham Moor landscape.

Enormous lake at the bottom of a unique cave system.

Patrick Dougherty's fantastic living tree sculptures, mind-blowing but temporary.

Where Agatha Christie mysteriously disappeared in 1926.

Once a farm where patients tilled the soil, this asylum lost its workforce when overmedicating became common practice.

The world's smallest movie theater runs on solar power—an attraction in itself.

A miniature Italianate fantasy village on the coast of Wales and the set of ITC classic "The Prisoner."

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

Eyam took steps to quarantine themselves and keep the plague from spreading.