During the mid-20th century, modernist concrete architecture was all the rage. The style was known as Brutalism—and while some people appreciated its sturdy functionality, other critics thought it was ugly. Marc Thomasset, an art designer/graphic designer in Brussels, Belgium, falls into the former category: As Curbed reports, he’s designed an adult coloring book that pays homage to famous Brutalist buildings, like William Pereira’s Geisel Library (the main library building at the University of California, San Diego) and the Marnix building, a large, modernist office building in Brussels.

The Brutalist Colouring Book features 32 pages of black-and-white architectural line drawings, allowing aspiring designers to add their own personal touch to concrete landmarks around the world. Five hundred numbered, first-edition copies are currently for sale online.

Thomasset fell in love with Brutalism as a young boy. Fueling his interest was a structure in his home city known as the CBR building, which the designer calls “quite unlike any other building in Brussels.” Thomasset tells website CityMetric that he hopes the coloring book “will help raise appreciation for this particular architecture style: the best known original Brutalist buildings are still threatened with demolition.”

Check out a few pages from the Brutalist Colouring Book below, and take some time to learn about Thomasset by visiting his website.

All photos courtesy of tmsprl.com

[h/t Curbed]