The Töölö football arena in Helsinki – nowadays known as the Telia 5G arena – was built between 1998 and 2000. Construction was preceded by an open architectural competition, which was won by Atelier 23, a Finnish-French bureau. The project was financed by the City of Helsinki, the Finnish state and the private sector. The project was led by businessman Hjallis Harkimo. The stadium’s principal and architectural designers were Ritva Kokkola and Olivier Lemarchand. A key architectural element in the cityscape is the curving steel roof over the main stand, for which the structural design was prepared by Heikki Järvinen, M.Sc. (Tech.). The roof is a demanding structure due to its long spans, and it weighs 700 tons. The stadium’s other structures are made from reinforced concrete. In spring 2017, KVA Architects Ltd drew up plans to develop the southern end of the stadium.