hired a guide at 300000Rp (Stefano is his name, a really jovial lad) shared between three of us. Started from Lake Kawar at 945am, and reached the top at 1210pm. Very good hike with only a brief rest stop at the rest point no. 3.
We went on a round crater tour, scrambling up and down the crater rim through pungent sulphur fumes.
Went down the same way in 2hrs time.
Climbed this while holiday in Sumatra. Great climb and wonderful views at the top.