The section between Leyton and just south of Loughton is the oldest railway alignment in use on the current London Underground system, having been opened on 22 August 1856 by the Eastern Counties Railway (ECR).
Strækningen mellem Leyton og umiddelbart syd for Loughton er den ældste jernbanelinjeføring i brug i det nuværende London Underground-system, efter at være åbnet 22. august 1856 af Eastern Counties Railway (ECR).