Two thousand artifacts from around the world collected by one woman who loved to travel.

Berthed at the Charlestown Navy Yard in Boston, "Old Ironsides" is the oldest commissioned warship still afloat.

There’s a hidden military meme engraved on the World War II Memorial.

Vienna's giant wonder wheel had a starring role in one of the greatest noir movies of all time.

The former private quarters and office of Dr. Sigmund Freud now hosts a museum housing the works of the founding father of psychoanalysis.

The beautiful baroque library of the Hapsburg empire.

Baroque celebration of the end of the Great Plague of Vienna.

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

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

Once the home of a hermetic monk, this cave now houses a small church.

A museum in the childhood house of a medical pioneer.

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

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

Mountain where Jesus was first tempted by the Devil.

Gaze upon chocolate sculptures depicting everything from chariot races to Gaudí's famous church at this shrine to sweets.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

An underground city of salt.

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

The silly symbol for an underground protest group is now scattered around the city.

A church of bones, decorated with 40,000 human skeletons.

Two stunning 17th-century libraries and a cabinet of curiosities.

The history of occult science is turned into a creepshow at this lurid Prague tourist attraction.