The railway carts travelers to central Athens's highest peak, which offers stunning vistas of the city.

This ancient hydrological marvel is now the base of a modern outdoor cinema.

This unusual elevator doesn’t stop or slow down.

Amsterdam's Red Light District leaves little to the imagination.

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

A hidden church in a hidden courtyard tells the story of the Miracle of Amsterdam.

A unique collection of gilded age mechanical pianos.

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

This unattributed sculpture in Amsterdam is hiding in plain sight.

Established in 1638 to battle the Black Death, Hortus Botanicus Amsterdam is a treasure trove of rare flora.

The world's only museum devoted to the wonders of fluorescence.

Largest illuminated advertisement sign in the world.

A beer pipeline runs beneath Bruges.

Meet the bronze beloved pet to a family of famous peeing statues.

Three floors of musical instruments coming from all corners of the world and hundreds of years of musical history.

A relic from the Industrial Revolution got a second life as a contemporary performing arts space.

Martin Bricelj Baraga's monolithic sculpture measures the blueness of the sky, and changes color to match it.

Hundreds of thousands of concrete bunkers crowd Albania long after the fall of Communism.

A naturally beautiful, seemingly bottomless deep blue spring.

An eclectic art form practiced by untrained masters is celebrated at this museum in the heart of Zagreb's old Upper Town.

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

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

The complex has been abandoned since the Croatian War of Independence, barring a stint as a set for 'Game of Thrones.'

The remains of a sunken military ship wreck visible through clear water.