London Underground with a few stations to the south of River Thames. The only London Underground stations in Zones 7 to 9 are on the Metropolitan line beyond Moor Park, outside Greater London. Some stations are in two zones, and the cheapest fare applies. Paper tickets, the contactless Oyster cards, contactless debit or credit cards and Apple Pay and Android Pay smartphones and watches can be used for travel. Single and return tickets are available in either format, but Travelcards (season tickets) for longer than a day are available only on Oyster cards. TfL introduced the Oyster card in 2003; this is
London Underground infrastructure London Overground – at New Cross and New Cross Gate. Of the boroughs that the Underground passes through, Hackney is served solely by Manor House station on the Piccadilly line in the very north-western edge of the borough. For the most part however some of the tube lines like the Central line skirt around the edge of the Hackney rather than going through it. Greenwich borough was unserved until North Greenwich station opened on the Jubilee line extension in 1999. The lines are electrified with a four-rail DC system: a conductor rail between the rails is energised at −210 V