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

A labyrinthine underworld of tunnels and caverns hides beneath the city.

Where the rules of that most quintessentially English game were first devised by an eccentric inventor.

The museum houses one of the world's largest shoe collections, boasting over 12,000 pairs.

The first place where the scientific innovation known as radar was first demonstrated in Britain.

This iconic building was founded as a school for the impoverished, but became one for the sons of the local gentry.

The longest and steepest staircase locks in the United Kingdom.

This medieval manor house was equipped with secret compartments for hiding priests.

Catacombs turned marketplace.

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

The quaint little store that is said to have inspired a famous Dickens novel was only given its name after the book was released.

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

London's creepiest cemetery was once the site of dueling magicians and mobs of stake-carrying vampire hunters.

Originally built for London’s cab drivers, this bright green hut now serves anyone a hot drink or meal.

The Metropolitan Police refurbished the blue box (perhaps not coincidentally) the same year "Doctor Who" returned to TV screens.

A local museum honors the overlooked discoveries of Mary Anning, one of the first professional fossil hunters.

This former quarry is now a vibrant labyrinth of magical in situ sculptures.

The only museum in the world dedicated to preserving the life and work of American comedian and entertainer, Phil Silvers.

Portugal's National Pantheon has a history of curses, collapses and financial problems.

Elaborately carved to showcase the glorious wealth that the age of exploration brought to the Portuguese empire.

This unreal Portuguese palace looks as though it's made from a pile of different castles.

A unique seaside cave where Aleister Crowley faked his own death.

A moving memorial to the fallen and missing from WWI trenches.

A rare example of World War I trenches from the British front.