While on the Island of Lombok I climbed Mt Rinjani with a tour group.  It was a fairly strenuous two day hike.  The mountain is not always open for climbing because in the center of the crater lake inside the outer mountain is an active volcano.  The mountain was actually closed from April to August of this year.

 

Here is a view of Gunung Baru or "new mountain" from inside the crater.  A lake has formed there and all of the bottled water on the island comes from here.  On the morning after the hike up the outer rim four of us decided to hike down the inner mountain to the lake for a swim and some pictures.  Sally and Roger, a British couple on their honeymoon are in the lower left of the photo above.  Olif, a German with a really nice digital camera is to the right.  The volcano gives off a loud noise like a jet engine in the distance and there is always smoke coming from  various holes in the exterior which spill out lava.  At night time you can see the red lava oozing down the mountain like molasses.