In Java you can find a number of epic locations to experience and photograph. If you're reasonably fit and are up to climbing a slightly hazardous mountain path (due to slippery stones on a fairly steep trail), then Ijen Crater should definitely get on your short list.

After a strenuous walk up a wide path in the dark, you descend down a narrow zig-zagged trail to the bottom of the crater. As you enter the crater you'll enveloped from time to time by whiffs of rotten egg sulfur smells.

One of the satisfactions about being a photographer traveling across Java is that you never know what great photogenic surprises you’re going to come across, but you know you will, & you'll occasionally be shouting to your driver, “Stop! Stop!  Stop! Pull over!”

This happened when we were careening across the rice paddies on the scenic route from Jogjakarta to East Java.  On that route you can't help but loving the unique beauty of the Trenggalek region.