By its meaningfulness, essentiality, and above all, by its megaron clarity (this term was coined by professor Tonči Žarnić), the Mašinogradnja (Engineering Industry) Pavilion at the Zagreb Fair fascinates today, as it did fifty years ago when it was created. This work by Božidar Rašica – a painter, scenographer, avant-garde artist, and professor who ‘used to open doors’ to his students, but primarily an architect – represents a firm point for a more ambitious architectural sightseeing tour in Zagreb.