Ordnance Survey Obelisk, Chingford, Greater London
This Ordnance Survey Obelisk was put up in 1824. It is made from granite, above eight feet high with battered sides and a flat top. There is an inscribed plaque inset. It was put up to mark the direction of the true north from the Royal Observatory at Greenwich. The meridian was changed in 1850 and the point of zero now passes 19 feet to the east of the Obelisk.
