The Bristol Flyers basketball team have competed in the British Basketball League, the UK's premier professional basketball league, since 2014. Bristol Aztecs play in Britain's premier American football competition, the BAFA National Leagues. In 2009 ice hockey returned to Bristol after a 17-year absence, with the Bristol Pitbulls playing at Bristol Ice Rink; after its closure, it shared a venue with Oxford City Stars. Bristol sponsors an annual half marathon and hosted the 2001 IAAF World Half Marathon Championships. Athletic clubs in Bristol include Bristol and West AC, Bitton Road Runners and Westbury Harriers. Bristol has staged finishes and starts of the Tour of Britain cycle race and facilities in the city were used as training camps for the 2012 London Olympics. The Bristol International Balloon Fiesta, a major UK hot-air ballooning event, is held each summer at Ashton Court.