Visitors dating back to the 1600s carved their marks in the stones of the iconic tower.

A Hungarian pharmacy museum with a box full of mummy powder.

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

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

The mummified right fist of a 1,000-year-old saint-king sits inside an ornate golden reliquary.

This off-beat, quirky communism-themed bar isn't afraid to poke fun at its history.

Time stands still at this serene burial ground in the center of Budapest.

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

A 19th century artistocrat's mansion, turned into a library, hidden in a modern library.

The home of a deceased Hungarian artist is now on display for visitors.

This dazzling Art Nouveau mansion is now home to the Modern Art Gallery Subotica.

This historical village takes you back to the 19th century.

Through the colossal entrance to this cave you'll find limestone tubs and an underground waterfall.

This natural monument has an origin story steeped in legend.

Its frescoes depict the likeness of Marshal Tito, Karl Marx, and Friedrich Engels burning in hell.

A curious little museum dedicated to the furry feline in the cat haven that is Old Town Kotor.

There's a mini version of Iguazu Falls hidden in the Balkans, and it's got a rope swing.

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

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

This beautiful 14th-century castle perched on a promontory overlooks the Bay of Trieste.

Europe's only Temple of Mithras located in a natural cave.

Two bronze wolves atop this large rock honor the "Wolves of Tuscany" brigade of World War I.

Originally a leper colony, the island is now an Armenian monastery that's home to an incredible manuscript library and eclectic museum.

Venice's "Island of the Mad."