The Colorado Convention Center is a multi-purpose convention center located in Downtown Denver, Colorado. At 2,200,000 square feet it is currently the 12th largest convention center in the United States. It opened in June 1990; the first event being the NBA draft for the Denver Nuggets. The convention center was expanded in 2004 to include several meeting rooms, two ballrooms and an indoor amphitheater. Since opening, the center hosts an average of around 400 events per year.