The Thames Gateway is an area of land stretching east from inner east London on both sides of the River Thames and the Thames Estuary. The area, which includes much brownfield land, has been designated a national priority for urban regeneration, taking advantage of the development opportunities realised by the completion of the High Speed 1 (officially known as the Channel Tunnel Rail Link) rail line. It stretches from Westferry in Tower Hamlets to the Isle of Sheppey and extends across three of the regions of England. The development is delivered through regional development agencies, special purpose development corporations and local partnerships.