The major public facility is the San Francisco General Hospital, a 580-bed acute care center that also serves as a regional teaching hospital. It is the largest acute inpatient and rehabilitation hospital for psychiatric patients in the city. The 23-acre hospital complex contains an internationally-recognized emergency and trauma center, psychiatric services, the nation's first AIDS unit, the Alternative Birth Center, and the innovative Women's Health Center. In 2003 the Avon Comprehensive Breast Center was opened, which planned to increase the number of underserved women who receive mammograms by 5,000 annually. Because of legislation passed in 1996 requiring that all California acute care hospitals meet upgraded seismic safety standards by either retrofitting existing buildings or constructing new facilities, San Francisco General Hospital is currently exploring options for rebuilding and relocating patients to a new campus by 2013.