My children complain that I force them to visit museums and historical sites whenever we vacation. I must admit, their accusations ring somewhat true. I enjoy learning about history and seek opportunities to educate them when we travel. But in my defense, I have allowed at least some fun on vacations: sand surfing on Kangaroo Island, Australia; a 15-mile bike ride through tulip fields in the Netherlands; a sled-dog ride in Alaska, for example.