Ujung Kulon National Park is the natural habitat of an endangered species of Javan one-horned rhinoceros. Handeuleum is an island in this national park. You can do many activities here—canoeing, trekking, camping—and there are also lodge accommodations.
For canoeing, you'll experience it exactly like Indiana Jones did in his films. Crossing the river through the dense jungle, you can find many animals—at least monkeys and birds, maybe snakes. Below the river you may be surprised if you spot a crocodile. You'll see the one-horned rhino only if you are very very lucky, because they are super-sensitive animals.