Millwall is a district on the western and southern side of the Isle of Dogs, in east London, England, in the London Borough of Tower Hamlets. It lies to the immediate south of Canary Wharf and Limehouse, north of Greenwich and Deptford, east of Rotherhithe, west of Cubitt Town, and has a long shoreline along London's Tideway, part of the River Thames. It was part of the County of Middlesex and from 1889 the County of London following the passing of the Local Government Act 1888, it later became part of Greater London in 1965.