The Championships, Wimbledon is the oldest and, arguably, most prestigious event in the sport of lawn tennis. Held every June or July, the tournament is the third Grand Slam event played each year, preceded by the Australian Open and the French Open, and followed by the U.S. Open. The tournament (which is the only one of the Grand Slam events played on grass courts) lasts for a fortnight, subject to extensions for rain. Separate tournaments are simultaneously held for Gentlemen's Singles, Ladies' Singles, Gentlemen's Doubles, Ladies' Doubles and Mixed Doubles. Youth tournaments - Boys' Singles, Girls' Singles, Boys' Doubles and Girls' Doubles - are also held. Additionally, special invitational tournaments are held: the 35 and over Gentlemen's Doubles, 45 and over Gentlemen's Doubles, 35 and over Ladies' Doubles and wheelchair doubles.