An underground nightclub helped spark a "Singing Revolution."

A massive ultra-modern church presents a science-fiction view of Catholicism's inclusive future.

Nose around a unique collection of more than 300 natural aromas used to craft fragrances.

An artsy hidden staircase leads to breathtaking views of San Francisco.

This shop and studio is dedicated to the art of the book, from letterpress to bookbinding.

A hidden subterranean installation offers a view of the sky.

This 19th-century church is now a popular roller rink.

In this century-old literary safehouse, print is alive and well.

This concrete tangle of square pipes has stood as a proud thorn in the city's side since the '70s.

With the touch of a button, you can read a randomly selected short story.

For almost 100 years, this site of peace and spirituality has existed on the California coast.

The oldest continuously operating church in California.

Learn about stars, weather patterns, or just enjoy the panoramic view of Ghent.

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

Rare wooden escalators lead deep down into an otherwise staggeringly monotonous tiled tunnel.

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

Most prolific publishing house in the 1600s open to the public.

This small condiment museum makes all manner of mustards with a 200-year-old mill.

The bones of the Biblical Magi traveled to Constantinople and Milan before landing in their current home inside an elaborate golden reliquary in the Cologne Cathedral.

Hamburgers are intensely proud of their tunnel beneath the river.

This dockworkers' lunch joint has been left leaning by a century of storm floods.

Model Trains and Much More in Hamburg.

Once the tallest building in the world, this abandoned church is now a monument to the destruction of WWII.

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