As the story I am currently working on is set in the romantic, thatched-roofed village of Wroxton in regency Oxfordshire, England, I went on a quest for old online maps of that area, looking for roads, terrain and surrounding communities. And, not for the first time, I found Rootsweb to be a great resource!
Traditionally a free online, well-cataloged warehouse of genealogical information and family trees, Rootsweb also offers gems such as lists of historical maps. Below are the ones I used for England, Scotland and Wales.
For historical Oxfordshire maps go here.
For other counties/areas of England, Scotland and Wales go here.