From the road the trail appears to lead off towards the coast up a small hill, but you're better off to take the stubby trail that runs off to the right which goes around this small hill and then rejoins and goes up the main slope.
It will take you about 45 minutes to get to the summit with some of the climb on chunky stone stairs, other bits along a more gradual dirt trail. You'll pass some small shrines along the way and also get some good vistas to the left and right as you climb.
The summit is home to a temple (don't forget your sarong) and the best viewpoint is out to the north. In a rather bizarre twist, the day we wandered (or rather, staggered) to the summit, we found a tall westerner standing at the photo point stark naked. Suffice to say that struck us as a little odd.
Aside from nude westerners, the temple and the trail to the summit is overrun with monkeys.
If you've got time up your sleeve, this is worth a look, but be warned, it is a strenuous climb and best not undertaken in the middle of the day without water!