Air Force, also internationally. It also houses the Prague Aviation Museum. The nearby Letňany Airport is mainly used for private aviation and aeroclub aviation. Another airport in the proximity is Aero Vodochody aircraft factory to the north, used for testing purposes, as well as for aeroclub aviation. There are a few aeroclubs around Prague, such as the Točná airfield. Cycling In 2018, 1–2.5 % of people commute by bike in Prague, depending on season. Cycling is very common as a sport or recreation. As of 2019, there were of protected cycle paths and routes. Also, there were of bike lanes and of specially marked bus lanes that are free to be used by cyclists. As of 2021, there are four companies providing bicycle sharing in Prague, none of them is subsidized by the city: Rekola (1,000 bikes), Nextbike (1,000 bikes), Bolt and Lime. Sport Prague is the site of many sports events, national stadiums and teams. Sparta Prague (Czech First League) – football club Slavia Prague (Czech First League) – football club Bohemians 1905 (Czech First League) – football club Dukla Prague (Czech 2nd Football League) – football club Viktoria Žižkov (Czech 2nd Football League) – football club HC Sparta Praha (Czech Extraliga) – ice hockey club HC Slavia Praha (Czech 2nd Hockey League) – ice hockey club USK Praha (National Basketball League) – basketball club Prague Lions (European League of Football) –American football O2 Arena – the second largest ice hockey arena in Europe. It hosted 2004 and 2015 Ice Hockey World Championship, NHL 2008 and 2010 Opening Game and Euroleague Final Four Strahov Stadium – the largest stadium in the world Prague International Marathon Prague Open – Tennis Tournament held by the I. Czech Lawn Tennis Club Sparta Prague Open – Tennis Tournament held in Prague 7 Josef Odložil Memorial – Athletics meeting World Ultimate Club Championships 2010 concluded in Strahov and Eden Arena Mystic SK8 Cup – World Cup of Skateboarding venue takes place at the Štvanice skatepark Gutovka – sport area with a large concrete skatepark, the highest outdoor climbing wall in Central Europe, four beach volleyball courts and children's playground, Central European Beach Volleyball Championship 2018 took place here. International relations The city of Prague maintains its own EU delegation in Brussels called Prague House. Prague was the location of U.S. President Barack Obama's speech on 5 April 2009, which led to the New START