Another extensive East London postal district, covering Chingford (and [Chingford Green]? to its north), as well as Highams Park to the south. At the very northern tip, the only London postcode to stray outside Greater London (into the Epping Forest district of Essex), are Sewardstone and Sewardstonebury. The London Borough of Waltham Forest covers the southern part of the district.
Auto-generated list of things in E4 (view them on a map):