A century-long search for a church that was never there.

The history of German architecture is explored across this fairy-scale mini-city.

A modern museum dedicated to the fairytales and dictionary work of the Brothers Grimm.

A sprawling Baroque park with 300-year-old hydro-pneumatic waterworks.

This romantic, decaying 13th-century ruin on the edge of Sherwood Forest is reputedly one of England's most haunted places.

There are hundreds of secret WWII bases hidden in British forests. Built to fight a Nazi invasion, they remained unknown for decades.

A ruined castle has more than its fair share of legends and ghost stories.

This historic abandoned train station looks like a stop for ghost trains.

The abandoned funicular tunnel was a secret base for the BBC during World War II.

A beautiful ruin of a 14th-century Plantagenet castle built by a medieval mercenary.

This magical museum celebrates the life and work of a seminal children's book writer (and occasional spy).

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

These lovely Turkish-styled baths were brought back to life after winning a reality show competition.

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

Harry Potter once visited this massive limestone cliff, which was carved by an ancient glacial river.

The wreck of a B-29 Superfortress now stands as a memorial left in the moors.

Terrifying derelict military hospital once housed a recuperating Hitler.

A rooftop restaurant hides in plain sight atop Vienna's Palace of Justice.

The world's largest collection of intentionally useless inventions.

This former insane asylum now holds a pathological anatomy museum.

The studio of Catalonia's most famous theatrical designer remains exactly as he left it.

This former Baroque palace on the historic Calle Montcada is a rare architectural gem and was once the meeting place of an aristocratic scholarly society.

The largest Art Nouveau complex in the world is a Barcelona hospital with a 600-year-long history.

The unexpectedly beloved remnants of a controversial thermal power plant.