This hidden green space is the city's second largest conservatory.

The anatomical-pathological collection of a man who changed surgery.

Famously misunderstood wonder of the ancient world

The world's largest collection of witchcraft regalia.

An unusual round church in London with a Templar past.

A vast overgrown cemetery, once known as one of London's "Magnificent Seven."

A special shop catering to the needs of things that go bump in the night, and also helps kids become writers.

The only university zoological museum in London houses extinct animals, bizarre natural history specimens, and a Micrarium of microscopic creatures.

A 1,215-foot tunnel transports pedestrians beneath the River Thames.

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

A 19th-century funicular railway shuttles visitors up this surprising sea cliff to one of the world's largest camera obscuras.

An amazing collection of curiosities hidden in a small Welsh village.

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

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

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

A subterranean playground in an abandoned slate mine.

A 4,500-year-old forest is slowly being revealed from beneath the sands of a Welsh beach.

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

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

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

This single-track road rewards brave drivers with stunning Scottish scenery.

One of Scotland's most important modern structures, it just made the '100 Most Endangered Sites' list.

A castle in the Scottish Highlands has been continuously inhabited since the 1300s.

The remains of a grand castle that may have inspired Bram Stoker's Dracula.