Destroyed Serbian army headquarters sits half crumbled in a largely revitalized Belgrade.

A Serbian church lit by chandeliers made of weapons.

A towering spire in the fortress of Kalemegdan honors the victorious armies of Serbia during their struggles against the Ottoman Empire.

Three connected pink triangles memorialize persecuted gays and lesbians throughout history.

Europe's official "zero-level," the equator of elevation.

A public urinal so pretty, it was declared a national monument.

Amsterdam's former hotspot for public executions and dissections.

This large copper bolt represents the benchmark for measuring sea levels in most of Europe.

The world's first zoo for microbes collecting the horrible and wonderful things living on and around us.

A beautifully eclectic mix of architectural styles.

A poignant museum dedicated to the history of the Dutch resistance against Nazi occupation

The world's oldest Jewish library was founded by Sephardic Jews in 17th century Amsterdam.

This city square is home to Amsterdam's oldest church and a statue honoring Dutch sex workers.

In the days before house numbers, these colorful signs held clues about various buildings' purposes.

One of Amsterdam's narrowest houses is located right across the canal from its widest.

The former home of a mad diplomat is said to still be marked in bloody, arcane scrawls.

A Dutch passageway's artistic, aquatic-themed makeover pays tribute to the capital city's famed waterways.

It appears as if a man is standing behind this giant airport clock, painting the hands in real time.

Come for the oysters, stay for the priceless art honoring inventors across history and Scotland's favorite outdoor sports.

An interactive exhibition space dedicated to the kinetic sculptures of Swiss artist Jean Tinguely.

An unassuming Swiss institution houses Europe's largest toy museum.

One of the world's largest collections of pharmaceutical artifacts.

The smallest museum in Basel, Switzerland, is a two-foot-by-two-foot window in the door of a 600-year-old house.

This artistic fountain display pays homage to this area's theatrical history.