Wimbledon is the oldest tennis tournament in the world, held annually since 1877 at the All England Club in London. It is one of the four Grand Slam tournaments and is unique as the only major played on grass courts, which are tennis's original surface. The 2012 Olympic tennis tournament was held at Wimbledon from July 28th to August 5th, featuring 172 players competing in singles, doubles, and mixed doubles events.