Description Brosella is a (kind of) free, open-air festival ran by mostly volunteers. Many legends as well as up and coming talents, local and foreign have been on our stages, in the unique setting of the Osseghempark, neighboring the Atomium monument. Any musician who has played here will tell you the same: Brosella is a beautiful, laid-back, warm festival where both the very diverse audience as the hospitably hosted artists quickly feel at home.