Don’t worry: if you haven’t heard of a rhombicuboctahedron, you’re not the only one. When the National Library of Belarus opened its new Minsk location in 2006, the shape—with its eight triangular and 18 square faces—left many scratching their heads.

The architects behind the project, Victor Kramarenko and Michael Vinogradov, chose the rhombicuboctahedron shape so that the library would resemble a diamond—a symbol of the beauty of the knowledge it houses. The glass panelling that covers the building, causing it to glimmer in the sunlight, only cemented their aim.

But Kramarenko and Vinogradov were faced with a problem: they wanted the 22-story National Library to glitter at night, too. So they decide to install a light show in the panelling.

Today, over 4,646 light fixtures cause the faces of the rhombicuboctahedron to change colors at night—a spectacular sight that has attracted many tourists.