The National Railway Museum in York is the largest railway museum in the world, attracting almost 1 million visitors per year.

The sculpture is made of more than 100,000 knives collected to raise awareness about violence.

Also known as "Leicester's Folly," this almost cathedral was left unfinished and in ruins.

This tower is all that remains of a once-famed chapel.

Picturesque ruins once held off mighty armies.

A look into the life of a Victorian-era prisoner.

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

This ancient abbey now lies in majestic ruin behind a caravan park.

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

This Norman castle has been the scene of assassination plots, religious persecution, and Nazi conspiracies throughout its long history.

These 1,500-year-old remains were found in a mysterious Anglo-Saxon mass grave.

One English town's celebratory landmark spurred more trouble than anticipated.

A landscape decorated with enormous skull sculptures.

A museum dedicated to the Spanish occult in a town that was terrorized by the Inquisition.

This Navarrese cave's history of witchcraft and pagan ritual is not just embraced, but recreated each year.

A collection dedicated to the treatment of disease, held in London's oldest hospital.

An incarceration museum on the spot of possibly the oldest prison in England.

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

A private selection of curiosities, carefully curated by a young Brighton local.

This Sheffield sculpture composed of 17,000 Allen keys honors both urban falcons and a furniture icon.

Long-secret natural history museum, featuring the skull of a "Terror Bird."

The painting on an aptly named street honors the 1980s slasher movie.

High Victorian fantasy created a fairytale castle out of a ruined fortress in Wales.

A mysterious artist-run cabinet of curiosities and library.