This once-forgotten oasis in the middle of Lisbon was first created over a century ago quite by accident.

This now abandoned restaurant provides some of the most amazing views of Lisboa.

This tile-work piece featuring a chicken riding in carriage is both a remarkable artistic creation and a social commentary of politics and culture in 17th-century Portugal.

This museum contains a vast array of puppets and marionettes from all over the world, featuring incredible works by Portuguese creators.

This network of conjoined cellars was riddled with traps and supposedly allowed the townspeople to pretend their homes were deserted.

Mysterious painted skulls in Moravia.

Folklore says this medieval fortress was plopped atop a portal to hell to trap the demons below.

A museum of alchemy and a basement laboratory all housed in an ancient building in a Gothic tower.

Bohemian paradise covered in majestic forests.

Europe's largest natural bridge has a 19th century royal chateau built into its side.

Europe's second largest ossuary wasn't discovered until 2001.

The hidden lair of an alchemist rediscovered in a 2002 flood.

The oldest private art gallery in all of Hungary.

Inside the Šomoška National Nature Reserve exists a unique rock formation rarely seen in the world.

A collection of intricate sculptures so small they have to be seen through a microscope.

The possible imprisonment of Vlad the Impaler here earned the medieval castle its nickname, "Dracula's Castle."

Once the legendary capital of the Dacian Kingdom, this city has been reduced to mere ruins.

A collection of items from a way of life that no longer exists.

Known as the Hintz House, this medieval pharmacy has been an apothecary's haven for nearly 450 years.

A celebration of all things tacky, garish, and bizarrely creative in the Romanian capital.

A muddy alien landscape that is home to rare species of exotic plants.

No one knows who built this strange cave of worship or exactly why.

The legendary cliffside castle of three-time Voivode of Wallachia, Vlad the Impaler.

Moss and stone turn this waterfall into an otherworldly liquid veil.