A floating cat sanctuary on an Amsterdam canal.

Amsterdam's narrowest house facade is a monument to 17th-century tax evasion.

The last of Amsterdam's original sea level markers remaining in place.

This $3 million model train takes you through Chicago, Seattle, and the thousands of miles in between.

Longest fortress system anywhere in Europe.

Gargoyle head that brings good luck.

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

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

A unique interactive experience of everyday life in communist Yugoslavia—a very different time in Croatian history.

This Croatian island is for sale but no one is buying due to the dozens of accused Nazi sympathizers who were massacred there after WWII.

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

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.

The interior of this church has been turned into a memorial to locals who died in Croatia's Homeland War.

The local club's soccer field is practically surrounded by UNESCO-protected monuments.

The medieval ferry service has been going strong since the 14th century.

Now harmless, this looming post struck fear into the heart of medieval troublemakers.

A musical instrument played by the sea.

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

This only museum in the world dedicated solely to mushrooms.

A peculiar museum that includes many drunken tales, a drunk driving simulator, and much more.

Where the lovelorn find a home for their sentimental keepsakes.

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

The author's beautiful and historic home is also a fully functioning goat farm.