A friend came to visit from off island and I had to take her to see Volcano National Park. We tent camped one night at this campground. It has toilets and a large pavilion, that we utilized to cook and eat under due to early morning rain. The night we stayed was verily quiet with not many other campers. I paid in the onsite dropbox with a check, but I am sure there is a way to probably pay online. Unfortunately there are no shower facilities.
The all time highlight is that when it got dark we made the 15-20 minute hike up to the Jagger Museum overlook/observatory to see the glowing lava in the crater.
The campground is technically outside of the national park and if you hike in there is no park fee.