This impressive collection of rare books on ancient mysticism inspired author Dan Brown.

Seven mini rowhouses fill the gap between 54 and 70 Westerstraat.

This functional solar system model was inspired by the famous Eisinga Planetarium.

A chain of 16 wondrous lakes formed as a result of the gradual dissolution of soluble layers of bedrock.

This narrow fjord-like bay is the largest ria in the Mediterranean Sea.

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

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

Just a few miles from Novalja, a strange geological oddity has left scientists baffled.

This military tunnel dates back to World War II and provides visitors with a little wartime adrenaline.

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

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

Built as an anti-fascist tribute, this surreal Yugoslav memorial became an unwelcome symbol after the Croatian war for independence.

A forgotten monument to Yugoslavian freedom.

This abandoned Croatian stronghold never saw a great deal of conflict but it is still a beloved relic nonetheless.

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

One of the best-preserved Roman amphitheaters is still used today, but for less brutal events.

The only gulag ever to exist in socialist Yugoslavia.

When Croatia became independent of Yugoslavia, the splintering governments left behind these concrete tunnels.

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

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

A wunderkammer of gold and silver reliquaries and ancient saintly bones.

Croatia's towering concrete blossom grows from the site of a World War II concentration camp.

The now-overgrown beach resort was once frequented by Yugoslav military elite.

This former estate of a fascist leader is now a burnt out ruin leading to a system of secret tunnels.