The other big activity we did was a helicopter flight over one of the volcanoes on Bali.
The village that has been established on the side of the volcano:
The site of the most recent lava flow - about 40 years ago:
Lava field, old caldera, caldera lake:
And a view from the helicopter of some rice paddies, which shows the amazing terracing they do on the hillsides.
If you ever go to Indonesia, and it is worth it, I recommend you pay attention to the weather. We didn't and went in the wet season, which meant that although it was very warm - about 31C every day - it also poured with rain every single day. Luckily all of our activities were in the morning and it rained mostly in the afternoon, but when it rained, it RAINED. As in, torrential downpours every single day.
You get used to that after a few days.