The Centre d’Observació de l’Univers main building hosts the interactive permanent exhibition on astronomy and space sciences. The exhibition is divided into three areas. It begins at the reception area dedicated to the Parc Astronòmic (Astronomy Park) and the role of astronomy in our society. The second area is the Universe Room, which presents a tour from the origin of the universe to the latest scientiﬁc discoveries. Finally, there is an innovative area, The Starlight Room, dedicated to the protection of the night environment against light pollution.