This mysterious underground cave in Shropshire dates back to the 18th or 19th century.

An 18th century monument regularly tagged with unsettling graffiti referencing a 1940s unsolved murder.

The site of an early Arthurian battle and the dwelling-place of prehistoric people and (possibly) an ancient race of giants.

Britain’s highest medieval monastery is a remote ruin nestled at the head of a valley 1,240 feet above the sea.

World's strongest whirlpool.

Tucked among the sand dunes overlooking a Welsh beach, a real-life tribute to a fictional elf.

Abandoned for over a century, this chilling train tunnel is now a destination for ghost hunters.

Secret Swing.

This urban oasis is a marvelous meld of music and landscape architecture.

One of the largest underground systems runs under Canada's largest urban center.

The oldest landmark of Toronto is a testament to shifting sands.

The Incredible Hulk, Yoda, Mulder and Scully, and many many others watch over the mean streets of Toronto.

One of the foremost Sherlock Holmes collections is hidden away at a Toronto library.

A unique collection of Science Fiction, Fantasy, and everything in-between.

Lost subway station nestled beneath Toronto's busy commuter line.

A collection of human remains, animal body parts, and other macabre curiosities all legally for sale.

A well-preserved network of cavernous tunnels have spent silent centuries removing Toronto's waste.

The Victorian-era greenhouse is stuffed with tropical plants, and open 365 days a year.

A 98-room castle in the middle of Toronto that bankrupted a 19th century electricity multimillionaire.

One of Canada's most incredible rare book collections holds hundreds of thousands of gorgeous tomes that the general public can touch.

A book collector's dream, this Toronto bookstore has the world's first "Biblio-Mat," a random book vending machine.

Read a book with a glass of wine at this classically restored bar.

The 2,000-year-old Roman columns are hidden within Barcelona's Gothic Quarter.

Bask in the 19th century grandeur of an eccentric Freemason millionaire's private gardens.