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.