 In the south-west of the parish, near Luton, there are the hamlets of Cockernhoe, Mangrove Green and Tea Green, and also the Putteridge Bury estate; these have LU2 postcodes and 01582 telephone numbers.Great Offley lies on the top of a chalk escarpment ridge (521 ft/159 metres above sea level) in the centre of the parish (the most north eastern ridge of the Chiltern Hills), and its population is 673.Offa, King of Mercia in the 8th century, is said to have built a palace here and thus gave his name to the village.