A lovely, and underused, resource that's been fantastic for my children is the the Cinema Museum in south London. It's well worth supporting - lots going on!
There's a lovely family event there on Saturday 10 November: "a nostalgic recreation of Saturday Morning Pictures from the 1950s, complete with cowboys, cartoons and cliff-hanging serials, not to mention choc ices, competitions, and a grumpy commissionaire."
[www.cinemamuseum.org.uk]