The Circle line forms an incomplete loop from Dhoby Ghaut in the Central Region of Singapore, north to Serangoon and Bishan, and south to HarbourFront, with a branch from Promenade to Marina Bay station which will be extended to HarbourFront in the future. The fully-underground circular route also makes several links with the other MRT lines. The line begins at Dhoby Ghaut station, which has an interchange with the North South and North East lines, going eastwards and paralleling Bras Basah Road and Raffles Boulevard, before joining the Circle line extension at Promenade station, which also interchanges with the Downtown line. From Promenade station, the line goes northwards and towards the east, passing beneath the Kallang Basin. Between the Stadium and Dakota stations, the line parallels Stadium Boulevard and Old Airport Road, then the line continues northwards and follows the route of Paya Lebar Road and Upper Paya Lebar Road between the Paya Lebar (which interchanges with the East West line) and Tai Seng stations.