King Street–Old Town station is a Washington Metro station in Alexandria, Virginia, United States. The station opened on December 17, 1983, and is operated by the Washington Metropolitan Area Transit Authority (WMATA). Providing service for both the Blue and Yellow Lines, this is the southernmost transfer station for the Blue and Yellow lines, as the two lines diverge just south of the station. During inclement weather, Crystal City is commonly used as an unofficial transfer point, being the southernmost underground station common to both lines. King Street was originally served only by the Yellow Line, until the Blue Line was extended from National Airport to Van Dorn Street in 1991.