A monument hidden in the woods built in 1938 as a getaway for a Dutch museum curator.

The ruins of a medieval castle that once belonged to one of the most powerful families in the Netherlands.

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

This massive mural by famed pop-artist Keith Haring was hidden for almost 30 years until its 2018 rediscovery.

Museum preserving torture methods from the past.

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

Seven mini rowhouses fill the gap between 54 and 70 Westerstraat.

Colorful and chaotic stacked hotel in North Holland.

This 22-floor tower's Skydeck offers panoramic views of Amsterdam.

The portrait of a man from Japan who sent weekly letters to a Dutch hotel he never visited.

A mural recalls a fictional woman who once lived at 23 Quai du Commerce, 1080 Brussels.

A fantastical 13th-century fortification sandwiched by a modern hotel in central Brussels.

This collection of over 50 murals celebrates Brussels' rich history as the self-proclaimed home of the "comic strip."

From Tintin to the Smurfs, Europe's greatest graphic icons are celebrated in a grand Art Noveau gallery.

Head underground and take a tour of the city's working sewer system, and see the underground river Senne, which defined Brussels for centuries before being covered in the 19th century.

Drink among marionettes at this pub inside a historic puppet theater.

A wonderfully kitsch bookstore the size of a supermarket.

The vast chamber inside this abandoned cooling tower looks like something out of a sci-fi dystopia.

The so-called "Statue of Liberty of Los Angeles" is on a one mutant mission to keep L.A. weird.

Hollywood's most famous landmark, the "temporary" sign that has stood for decades longer than intended.

Hidden in the hills of Hollywood, this secluded Oz-themed garden is dotted with dozens of thrones.

One man's homage to the sun continues to grow like a glass fractal.

Shop selling 500 flavors of soda has something for everyone.

America's most famous piece of self-built architecture.