This museum in the tower of the oldest church in Gdańsk, is home to centuries-old time-keeping devices and the world's first pulsar clock.

This sprawling concrete suburb of Kraków was designed by the Soviet Union as the model proletarian city.

St. Mary's features one of the most spectacularly decorated cathedral interiors in all of Europe.

This Polish cave has housed a dragon, a brothel, and an enduring legend.

The former Nazi concentration camp stands as a museum to remember this dark chapter in European history.

An underground city of salt.

This hauntingly beautiful cemetery outside a medieval citadel is full of winding paths and ivy-covered graves.

Romania's triumphal arch looks out over Bucharest.

Nine centuries-old fortresses guard the walls of this medieval Romanian city.

A stunning 18th century pharmacy and medieval chemist's collection.

A fire once nearly devoured this gorgeous 14th-century Gothic cathedral.

This communist behemoth is the heaviest building in the world and a legacy of a brutal regime.

The European towns of Brașov and Râșnov each have proud signs reminiscent of the Hollywood sign.

Something's watching you.

This snug medieval lane is one of the narrowest streets in the world.

This once-derelict building is now one of the most beautiful bookstores in the world.

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

This elaborately decorated, fairytale-like Romanian royal palace is one of the most striking castles in Europe.

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

Go inside to really appreciate this 500-year-old technological masterpiece.

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

Florentine Renaissance style building in Switzerland, home to the world's largest taxidermy Great White Shark.

This strange statue features a bust of the famous composer plopped atop a woman's body.

The world's oldest known salt mine.