London Underground ticketing destinations and most interchange stations are in zone 1, meaning that most journeys over similar distances will cost the same. A few stations in the north east of the network, on the Central line, outside Greater London (in the Epping Forest district) are in zones 4, 5 and 6. In the north west of the network, on the Metropolitan line, zones 7, 8 and 9 (formerly A - D) cover stations outside Greater London including Amersham and Chesham in the Chiltern district of Buckinghamshire. Unlike the lower numbered zones, these ancillary areas do not encircle the capital. Some stations are
R25 (London) Gospel Oak to Barking Line and a provision for a stop at Renwick Road (if needed) and states that a further extension across the Thames should be provisioned. R25 (London) R25 is a possible railway orbital around the Zone 3 area of London, England. The proposed line would use some existing lines by National Rail and London Overground. Issue 755 of "Rail Magazine" (20 August 2014) says that the Mayor of London has started consulting on a new Zone 3 orbital railway, the 'R25'. The nickname alludes to the M25 orbital motorway. The idea featured in news media when the