There is a great park right by where my in-laws live that we get to visit nearly every time we're there. It has an REAL steam train, an old-fashioned carousel and a great petting/feeding farm. The kids loved it, especially Charlie (as you can see from these photos).
London Bridges falling down with Maddie and Grandma.
Waiting for the train.
Charlie was thrilled and terrified evertime the train let off steam.
Amazingly Charlie was able to lure most of the farm animals down from their pasture just by picking up some sticks and calling "come here little cow! i have some treats for you." I think it worked better even than the kids who had stalks of celery and bunches of lettuce.