Denver Federal Center, surrounded by Lakewood, Colorado, is part of the General Services Administration and is home to about 6,200 employees for many Federal government of the United States agencies. The Denver Federal Center encompasses an area of about 670 acres (2.7 km2) and has 90 buildings comprising over 4,000,000 square feet (400,000 m2) of office, warehouse, lab and special use space. There are 26 different Federal agencies on-site, making it the largest concentration of Federal agencies outside of Washington, D.C.