The decaying ruins of Wales' first asylum for the mentally ill.

Once thought to be the mysterious work of a witchy prophetess, a well with unusual properties turns objects into "stone".

The oldest continual pilgrimage site in Britain was supposedly created by a gruesome beheading.

The longest and tallest aqueduct in Britain can actually be sailed across.

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

The sign at the garden gate reads: "These Plants Can Kill."

The largest greenhouse in the world is home to over one million types of plants.

A unique waterfall that some believe attracts the fairfolk.

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

The gloomy ruins that inspired Bram Stoker to bring Dracula to life.

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

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

Cliffs full of fossils at the portal to England's Jurassic Coast.

Huge concrete structures designed as an early warning system for Britain to detect enemy aircraft.

Surreal riveted sea forts once protected the Kent shores from German attack.

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

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

A magnificent Victorian garden that brings the charm and style of old-time aristocracy to the 21st century public.

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

Gothic tower mentioned in Thomas Hardy poem "The Channel Firing."

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

Gothic tower where Lord Alfred Tennyson wrote the poem "The Sleeping Beauty."

Abstract dinosaur models in London.

England's oldest surviving hedge maze has been confusing visitors for over 300 years.