781-1 Hiji, Kunigami, Kunigami District, Okinawa 905-1413, Japan
goo.gl/maps/3vp815gHp5ZjjtCU9
Hiji Falls National Park is a well developed hike that is very safe in northern Okinawa, Japan. It costs Yen to hike, but is taken care of and is very beautiful. It's not really easy because of all the stairs, but it's worth it. Most people over 5 or 6 years old shouldn't have too much of a problem with the hike. There is also a campground at the base of the hike.