This rock formation has some fun climbing to offer at a reasonable rate. It's not far from the road and there is a small pullout at the bottom of the trailhead.
As your heading East into the Canyon you'll see a stone brick formation. These are not far from the waterfall and on both sides of the road. Larger and more pronounced on the So (right side). I believe these were the old sign markers for the canyon.
Near the stone formations there are 2 small pullouts. Continue East along the road for a short distance and you'll see the trail move off to the right, up the hill side. "The Diamond" is easily seen due South of the road.
Learnintoclimb's photo is a good shot of the stone formation and "The Diamond" proper.