 The independent cities of Manassas and Manassas Park are surrounded by Prince William County.Before becoming independent cities in 1975, as are all cities in Virginia, both were towns and officially part of the county.The Prince William County Circuit, District, Juvenile and Domestic Relations Courts, Prince William County Commonwealth Attorney's Office, Prince William County Adult Detention Center, Prince William County Sheriff's Office, and other county agencies are located at Prince William County Courthouse complex.