Clean restrooms, coin-OP showers, very well-maintained fire pits, and within biking or walking distance of the visitor's center (where the tours run from).
Definitely book cave tours in advance. When I visited they only had one walk-in tour available due to Covid restrictions.
It was still worthwhile!
Also was able to hike most of the trails in the main part of the park in a four-hour morning.
More trails are accessible via Green River Ferry on the other side of the river.
Also, check out the kayak/canoeing rentals in the area.
I have my own kayak and found a service that would drop me off and pick me back up 8 miles down the river for $30!