Cambridge - will you retire at Wicken Fens? I've been reading about the Saxon resistance in the years after the Norman invasion and subjugation.
Please don't mention The Fens! It is synomous with interbreeding and webbed feet!
Overall I would choose to retire to Kent: housing good value for money, good road network, near the coast, nice beaches, some hills, easy access to London rail and road, easy access to Gatwick and Stansted, ports, Eurostar and Europe. Decent locally produced ale and wine. What's not to like? It's very underrated in my opinion.