When DS was 3 we took him to DL and DCA. We rented a stroller but he's always preferred to walk and we never really minded becasue the stroller gave us a great place to stash all of our stuff while we were in the parks. He was always really good about holding someone's hand but since it was so crowded that visit, we put one of those plush animal "backpacks" with the little leash on it on him just in case we got separated in a crowd. Needless to say, everywhere we went the CMs would ask him, "Did you know you have a monkey on your back?" My favorite was when Mary Poppins and Bert asked with their accents!