We hiked through here on a day hike through the crater, and stopped here to rest and chat with some campers. The campground has one cabin available to reserve online (but reservations fill up fast) and then a grassy area to camp with a tent in. The guys we talked to said it was constantly raining the night before, so they camped in a small lava cave near the campground. It was a beautiful area of the crater to be in - truly 'in the clouds' - but it was misting the whole time we were there and I'm not sure I'd want to spend a night there if it was in a tent. The cabin seemed well maintained. There's an outhouse/toilet there, as well as water that must be treated/filtered. It was about 6-7 miles in, starting from the Sliding Sands Trail, or about 4 miles from Halemau'u Trailhead.