We were so fortunate to be able to travel so much with our boys. Japan has beautiful national parks and one we visited in January 1981 when Leif was six years old was Hakone. This park is in a volcanic area, and I remember Leif being fascinated with a place where you could hard-boil and egg in a sulfur spring. The practice was so popular that the area was completely littered with peeled-off eggshells. We didn't know about this before we got there and didn't bring any eggs to cook, but Leif enjoyed stepping on the shells and smashing them. :)
We also got this beautiful, clear view of Mt. Fuji, which is often shrouded in clouds, fog, or, if you are trying to see it from Tokyo, smog. It was a lovely but very chilly day in Hakone. We also ate some wonderful hot noodles at a local restaurant. Leif liked Japanese food, especially tonkatsu (deep fried pork cutlet, much like Wiener Schnitzel) and the noodle soup dishes.