Blackwall is an area of the East End of London, situated in the London Borough of Tower Hamlets on the north bank of the River Thames. The district around Blackwall Stairs was known as Blackwall by at least the 14th century. This presumably derives from the colour of the river wall, constructed in the Middle Ages. The area lay in a sheltered loop of the river next to Poplar's East Marsh, where the East India Docks were constructed at the beginning of the 19th century Contrary to expectations, the River Thames landmark named Blackwall Point is not located in Blackwall district but on the northern tip of Greenwich Peninsula, which is south of the Thames. It is so named after the Blackwall Reach of the Thames. Today Blackwall is perhaps most well-known for having given its name to the Blackwall Tunnel, which passes south under the adjacent River Thames to north Greenwich. Blackwall is also the location of a fictitious fire-station featured in the London Weekend Television series London's Burning. There was a railway from Minories to Blackwall via Stepney (called the London and Blackwall Railway). It ran a distance of three and half miles. Much of the current DLR track around Limehouse and Blackwall is on the old viaducts. This was authorised in 1836 as "The Commercial Railway", running close to Commercial Road in the East End. It has been the home of such noted seamen as Horatio Nelson and Walter Raleigh. In 1606 it was the departure point of the colonization of North America launched by the London Company.