The ''Red Line'' (also known as Coast Line) will extend through Doha, running from Al Khor to Al Wakrah and Hamad Airport via the Red Line North and Red Line South. Doha Metro's ''Green Line,'' or Education Line, connects Doha to Education City and Al Riffa. Starting in Old Airport, the ''Gold Line'' (also known as Historic Line) will end in Al Rayyan and cover a distance of 30.6 km. Lastly, the ''Blue Line'', or City Line, will only cover the inner city of Doha, and is planned to be semi-circular with a length of 17.5 km.