Beautiful mountain, ruined by trash, just like many other Indonesian mountains.
I started from and descended back to Kersik Tuo.
The first long part of the trek is through a dense rain forest. It gets very slippery when it rains and in my SE Asia mountain experience, it rain a lot!
The path is very steep. You will have to use both hands climbing from shelter 2 to shelter 3, so tuck those sticks into your backpack :)
Shelter 3 is just at the exit on the jungle, and you can see the peak from there. It's a rocky path from there, really steep, and you will have to get down on all 4 in some parts. Be careful where you put your feet as the rock is not that solid.
View from the summit was beautiful, I was lucky to have a clear sky. You can look down into the crater but all you will see is smoke coming out. Watch out for those clouds coming out of the volcano as you go up, they smell really bad:)