To enter this cluttered-yet-cozy sanctum of Belgian brews, ring the bell and tell the gatekeepers you've come “to taste beer.”

This small corner bar is home to a rare 1930s dance organ that still plays tunes for one Euro.

A former ironworks that was the first UNESCO industrial site.

This fairytale castle was built as a show of power but was nearly torn down thanks to its history of torture.

Each time a baby is born in Ghent, these streetlights flash in silent celebration.

This narrow Ghent alleyway is an officially sanctioned street art tunnel.

The world's largest bicycle shelter can hold more than 12,500 two-wheelers.

This small town in the Netherlands has no roads but instead, miles of canals and over 100 bridges.

This unique bridge physically lifts a piece of the road into the air to let boats pass by.

This beautifully designed star-shaped fort was the premier defense system of the late 1500s.

This giant radio telescope would be a rusting ruin if it hadn't become such a beloved relic.

An awe-inspiring giant blue whale jaw bone stands in the center of this Dutch island.

A radio telescope for listening to the stars, based in one of the cloudiest countries in the world.

Remarkably preserved body discovered in a peat bog.

This imposing tower named after the mythical sword of King Arthur is considered the tallest freestanding climbing wall in the world.

Every winter, this former planetarium is transformed into a massive, brightly-lit Christmas ornament.

This Paris art space celebrates the creativity and ingenuity that springs from abject poverty, especially in Africa.

Hidden away in a modern library are the remains of one of the 18th century's most celebrated wunderkammers.

This former “ante-chamber to the guillotine” has been refurbished to illustrate the brutal history of French justice.