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

This Gothic Revival castle used as a shooting location for "The Secret Garden" and other films.

A glorious pub known for a spiteful printing feud and its famous typeface lost—then found—at the bottom of the Thames.

A friendly pub with a sordid past in cock fighting.

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

Stonehenge has nothing on Castlerigg’s views.

A mysterious pair of mice eating a piece of cheese is London's smallest public sculpture.

A famous burial ground with a history both grim and literary.

Possibly the oldest living thing in Europe, more likely a pagan survivor.

A village on the east coast of England that has almost completely eroded into the North Sea.

No one knows who created the statues or if they are arranged properly—let alone the artwork's real name.

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

These stark white cliffs were spat up by the sea and are slowly being retaken by it.

There are plenty of wonderful panoramic vistas in Edinburgh, but not many are hidden smack in the middle of the Old Town.

The granddaddy of English geoglyphs dates back to the late Bronze Age.

Hidden in a grotto 26 feet below Nottingham's oldest hotel, this stylish subterranean drinking den is notoriously hard to find.

This hospital once pioneered the use of electroencephalograms, but fell into maltreatment, abuse, and eventual abandonment.

J.R.R Tolkien, C.S. Lewis, and other "Inklings" met at the Oxford pub to discuss the now legendary fantasy stories they were writing.

An abandoned tank sits in an empty London lot as a symbolic middle finger to local city planners.

London's largest outsider art museum.

In Twickenham sits a small whitewashed castle that inspired Mary Shelley's 'Frankenstein.'

St. Mary's Asylum was isolated and abandoned before being converted into a Bed and Breakfast.

A local tree surgeon has created a whimsical walk full of carved tree stumps near Scotland's Loch Lomond.

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