The larger central number is the main sheet: if present, the numbers 1-16 indicate that the Ordnance Survey produced a map of that area. Click on the sheet required to view which (if any) sheets are held by Durham University Library.

Members of Durham University or other subscribing institutions can access historic Ordnance Survey maps via EDINA

For a comprehensive online mapping service for modern (post 1974) County Durham, see Durham County Council's site at http://www.durham.gov.uk/durhamcc/usp.nsf/pws/GIS+-+Online+Mapping