Inside this small chapel tucked away in the forest is one of the most well-preserved Danse Macabre frescos.

Island wonderland for communist autocrats.

This 135-year-old weather station studied the effects of the climate on human health.

A peculiar museum that includes many drunken tales, a drunk driving simulator, and much more.

The oldest arboretum on the Dalmatian coast doubles as the gardens of Kings Landing in "Game of Thrones."

This scale model of our solar system hid in plain sight for years before a physics team sought out all the planets.

Longest fortress system anywhere in Europe.

Humble beginnings for one of the world's most famous scientists.

The remains of a sunken military ship wreck visible through clear water.

Legend has it fairies gathered at the site of this medieval castle.

Large, airy hallways hide within an impenetrable fortress that beckons urban explorers.

This truly palatial work of Communist-era architecture now sits crumbling on a Croatian beach.

Yugoslavia's biggest underground airport lies in ruins.