The BNP Paribas Open is an annual tennis tournament held in the city of Indian Wells. The tournament is a Masters 1000 event on the men’s tour and is a Premier Mandatory event on the women’s tour. The event is one of two tour events in which main draw play extends beyond eight days. The tournament is the best attended tennis tournament outside the four Grand Slam tournaments, with over 300,000 visitors during the event. It has the second largest tennis stadium in the world.