From the Pali Hwy take the Old Pali Road in Nuuanu. Trail head is near the watershed and marked with concrete pilings on the side of the road to block cars from entering the trail.
It rains daily, so be prepared for muddy trails. DO NOT leave anyting in your car as the parking is roadside and deserted.
Trail through a tropical rainforest. Many native plants and birds, a few waterfalls.