I am taking my kids berry picking this month. There is also art classes for older kids where I live. There is all sorts of farm that we can visit for free as well but I am very rural. You can do museums some libraries offer passes sometimes for free. I often buy outing off of groupon to save a few dollars on entrance. Some local fairs offer free entry to children. At least they do in my area. I think you already have a lot of options with what you listed.