This hidden art nouveau gem was designed by an architect in search of a national style.

A museum dedicated to a secret military hospital hidden beneath a castle in Budapest.

Uh, pardon me, ma'am, but I couldn't help noticing that there's a Columbo statue in the middle of Budapest.

Sitting beneath an unremarkable residential building is a museum devoted to classic Pinball.

Museum dedicated to the terror regimes of Hungary.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

A series of caves under Castle Hill that once held the prisoner Vlad Tepes, better known as Count Dracula.

This Hungarian castle was built out of cardboard and wood until it proved so popular that it got upgraded to stone.

This Budapest bar allows drinkers to leave their mark on the walls, floor, and even ceiling.

At just 51 feet and 10 inches long, it's the shortest street in England.

All unmarked mute swans on the Thames are owned by the Queen per a tradition that began in the 12th century.

You can spend the night in Dr. Frank-N-Furter's castle.

A replica of the steam engine that hauled Queen Victoria's Royal Train is on display at Windsor.

The bizarre visions of H.R. Giger, tucked away in a Swiss medieval city.

This memorial commemorating fallen Swiss Guards of the French Revolution has been called the saddest stone in the world.

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

A space dedicated to contemporary art and culture, co-chaired by fashion icon Miuccia Prada.

An ossuary built in 1210 to collect bones from the Ospedale Maggiore of Milan.

Milan's duomo is covered in beautiful carving including a curious "dinosaur-like" beast.

A fascinating insight into daily life in the Eastern Bloc.

One of downtown Berlin's last reminders of its Communist past.

Auguste Maïcon, a pioneer in French aviation, was born in this house in 1891.

The unique waterfall in Iceland's south features a backdrop of geometric black lava columns.

This valley of hot springs and boiling mud pots is home to the record-holding "Geysir," which originated the English word.