This is one of my favorite places to go cool down when we are in the area. Despite the tiny gnats (?) that tend to swarm you when you stop moving, it really is a nice, fun and easy place to get to. The parking is limited so try to carpool or expect to walk a bit farther.
Once you park, follow the parking lot to the start of a path near some bathrooms that will say its the trail to Mossy Cave. You dont have to hike up to the 'cave' even though its just 0.4 miles. It's a steep'ish climb at first, but less than 20 steps probably and then the ground is fairly even to walk on. You will pass a couple bridges on your way to the waterfall that are great for taking photos on or crossing the water to get towards the cave.
Now....let me get a selfie....
Smokey skies from the Brian Head fire
Too close to comfort for me!