Since the turn of the 21st century, Copenhagen has seen strong urban and cultural development, facilitated by investment in its institutions and infrastructure. The city is the cultural, economic and governmental centre of Denmark; it is one of the major financial centres of Northern Europe with the Copenhagen Stock Exchange. Copenhagen's economy has seen rapid developments in the service sector, especially through initiatives in information technology, pharmaceuticals and clean technology. Since the completion of the Øresund Bridge, Copenhagen has become increasingly integrated with the Swedish province of Scania and its largest city, Malmö, forming the Øresund Region. With a number of bridges connecting the various districts, the cityscape is characterised by parks, promenades and waterfronts. Copenhagen's landmarks such as Tivoli Gardens, The Little Mermaid statue, the Amalienborg and Christiansborg palaces, Rosenborg Castle Gardens, Frederik's Church, and many museums, restaurants and nightclubs are significant tourist attractions. The largest lake of Denmark, Arresø, lies around 27 miles (43 kilometers) northwest of the City Hall Square. Copenhagen is home to the University of Copenhagen, the Technical University of Denmark, Copenhagen Business School and the IT University of Copenhagen. The University of Copenhagen, founded in 1479, is the oldest university in Denmark. Copenhagen is home to the FC København and Brøndby football clubs. The annual Copenhagen Marathon was established in 1980. Copenhagen is one of the most bicycle-friendly cities in the world. The Copenhagen Metro launched in 2002 serves central Copenhagen. The Copenhagen Metro is scheduled to expand radically with the opening of the City-ring line during fall 2019, the new line will connect all inner boroughs of the city by metro, including The Central Station, and will open up 17 new stations for Copenhageners. The new metro line is a part of the city's strategy to transform mobility towards sustainable modes of transport such as public transport and cycling as opposed to automobility. Additionally the Copenhagen S-train, the Lokaltog (private railway) and the Coast Line network serves and connects central Copenhagen to outlying boroughs. To relieve traffic congestion, the Fehmarn Belt Fixed Link road and rail construction is planned, because the narrow 9-9.5 mile isthmus between Roskilde Fjord and Køge Bugt (Køge Bay) forms a traffic bottleneck. The Copenhagen-Ringsted Line will relieve traffic congestion in the corridor between Roskilde and Copenhagen. Serving roughly two million passengers a month, Copenhagen Airport, Kastrup, is the busiest airport in the Nordic countries.