Ordnance Survey Maps – National Library of Scotland
Good source of historical OS and other maps at Vision of Britain
Foxearth Local History – local maps
L Brown Collection – no re-use.
David Rumsey Collection – excellent.
OMNIA – Europe’s Culture in One Place – should access everything including Spanish Library.
Discover Europe’s digital cultural heritage | Europeana
Gallica (bnf.fr) – French National Library – excellent.
University of Utrecht – A huge amount of Open Access documents accessible by alphabetic index. Possibly a treasure trove but too big to look through. Wagenhaer and Blau Atlas’s are but two.
National Archives NextGen Catalog
Vintage Maps – excellent selection: (Grahame Spence Charts – If you like to download the image of this map with a resolution of 1200 pixels, please follow the link below. You can use this image for publication on your personal or commercial websites for free if you set a link to this website. If you need photographs with a higher resolution, please contact us.)
Some Charts – useful information.
Tree Search – Ancient Tree Inventory (woodlandtrust.org.uk)
Images
Search, download and print PICRYL – Public Domain Media Search Engine images, albums, collections
Images at US Library of Congress
Online Library of Selected Images
Archives of Aerial Images
IWM GERMAN SECOND WORLD WAR AERIAL RECONNAISSANCE COLLECTION (not online))
National Archives Collection of Foreign Records Seized US archive, detail on target areas.
https://www.alliedairforceresearch.com/post/hitlers-uk-pictures not easy to search.
https://archiveshub.jisc.ac.uk/search/archives/04deb770-003d-38a9-8fb5-5f802270a13f leads to this Search | NCAP – National Collection of Aerial Photography nothing useful for 1944.
Geographic Military Maps and Aerial Photographs, ca. 1943–1980 not yet online.