Millwall Dock is a dock at Millwall, south of Canary Wharf on the Isle of Dogs, in London. The Millwall Dock was constructed by John Aird & Co. to a design by Sir John Fowler and opened in 1868. The dock is L-shaped, with an 'Outer Dock' running east-west, and an 'Inner Dock' running north from the eastern end. It originally contained around 36 acres (14 hectares) of water and had a 200 acre (81 hectare) estate. The western end of the Outer Dock was originally connected to the Thames at Millwall by an 80 ft (24 m) wide channel. The spoil from the docks formed the area of wasteland known as the Mudchute. A graving dock for ship repairs was constructed at the SE corner of the Outer Dock (one of 6 originally planned), and later lengthened to 555 ft (169 m).