This memorial to a murdered empress took 20 years to design, then spent 30 years hidden away in storage.

From Austrians to Nazis to Soviets, this historic Budapest fortress has a history as complex as the city itself.

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

Some of the greatest minds in the history of Hungarian art and science converged in this café.

The holes in this wall provide a glimpse into Jewish life in Budapest, both past and present.

This quiet, unassuming spot in Budapest was the birthplace of the bloody 1956 Hungarian Revolution.

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

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

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

Where the lovelorn find a home for their sentimental keepsakes.

A World War II evacuation tunnel turned into a history display of Croatian state and people.

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

Now abandoned, the world's first torpedo factory is crumbling into the sea.

Croatia's "hairy stone" fortress is one of the most well preserved Istrian castles.

The Renaissance-era courthouse is a relic from the fortified town's centuries of Venetian rule.

A wonderfully strange collection of 500+ stuffed frogs doing people things.

The big toe of this towering monument to a Croatian national hero is worn from years of superstitious rubbing.

When a supermarket opened up shop within a medieval building it became protected by UNESCO on a technicality.

An ethereal glowing blue ocean cave in Croatia.

Formerly Yugoslavia's "forbidden island," this sleepy little city still holds the abandoned remains of military strongholds.

Longest fortress system anywhere in Europe.

An ancient knight and a symbol of the city's freedom.

A full figure 4th century incorruptible saint lies in a glass coffin in Croatia.

Gargoyle head that brings good luck.