The section covering the National disc has been expanded with a new section covering the Domesday surrogate walks (better known as virtual walks these days). This 'street view' like feature was one of the innovations of the Domesday system and allows you to walk around towns, forests and homes from the 1980s. The new guide includes screen-shots, plans and real-world locations (where known) for all of the 9 available walks.
Please see the National disc Surrogate (Virtual) Walks page for more details.