Ball Arena is a sports arena in Denver, Colorado. The arena opened on October 1, 1999, and is the current home to the Colorado Avalanche of the National Hockey League (NHL), the Denver Nuggets of the National Basketball Association (NBA) and the Colorado Mammoth of the National Lacrosse League (NLL). Ball Corporation currently has naming rights for the arena. The arena currently seats 19,155 for basketball and 18,007 for hockey and lacrosse.