Location - Yomitan. Traveling north on the 58, note the restaurant/factory with a huge fake cow and 2 fake pigs outside. About 800-1000m after that, there is a right hand turn off into the middle of nowhere (no light). This deadends at a fence (the Kadena perimeter). You can park there, or if that seems to unpleasant, then turn left before you reach the gate. The road curves around and runs into another fence, but the guard there wants you to park out of his sightline.
This is a network of trails apparently created and maintained by the Okinawa Mountain Biking Assoc. So, if on foot, watch out for your adrenaline-seeking comrades. The trail follows the fence for a while, and there are lots of turn-offs into the forest, some of which are signposted by OMBA. The maps online are not super helpful. There is some interesting scenery here, including an old helicopter landing zone and a great example of hillside erosion. From the ridgeline there are spotty ocean views. It is possible this trail links up with the one in the Yamada stone bridge area (ie La Luge if you are a mountain biker) but we cannot find a map demonstrating that yet, and have not walked far enough to find out for ourselves.
As always, take water, light provisions, and a stick for clearing the spider webs. It is pretty slushy after a big rain.