Ordnance Survey map edition 1939; area between High Holborn and Farringdon Road showing Holborn, the City of London, Theobald's Road, Gray's Inn Road, Chancery Lane, Holborn (street), Clarkenwell Road, Hatton Garden, Holborn Circus, St Andrew Street, Holborn Viaduct, Lincoln's Inn Fields, Lincoln's Inn, Gray's Inn, Staple Inn and Barnard's Inn.