Engulfed by craggy outcrops and the sound of crashing waves, the secluded grounds of the national park headquarters are a gloriously serene place to stay, with simple four- to eight-person bungalows or tents. There are toilets and running water, and there's also a shop but you'll need to bring your own food. You can also get permission for camping on Ko Rok here.
The road to the national park headquarters fords the klorng (canal; also spelt khlong), which can get deep during the monsoon.