MauiGuidebook.com Rating: 
In a nutshell: A nice place to go to the bathroom.
Minuses: Waterfall and pool are small and crowded.
Sound-bite: “Just don’t look down!”
If you need a rest stop with bathrooms, this five acre state wayside is a good option. There are also covered picnic tables and a small waterfall with plunge pool.
The only part worth stopping for here are the bathrooms, but if you need to schedule a stop, once out of the car it can be a convenient and fairly nice place to sit down at the tables and take a break. The pool really isn’t worth a dedicated stop when compared to all your other options in on the Road to Hana.
There is another pool upstream, but it requires a hike through mud and then the correct decision on which way to go (simplified: head upstream), then a dangerous walk across a viaduct. (There are plenty of viaducts in this area, so you may wind up on a dangerous wild goose chase.) Bottom line is that if you’re willing to go to these kinds of efforts to get to a nicer pool, don’t put that effort out here – there are many nicer pools worthy of your efforts just outside of this park!
Key Info:
Mile Marker: #22.6 (Hana Hwy aka Hwy 360)
GPS Coordinates: 20.817275,-156.125073
Facilities: Restrooms, picnic tables, trash cans, no drinking water
Get directions
View Pua’a Ka’a State Wayside in a larger map
JOHAN says:
BEAUTIFUL.
Road to Hana Guide says:
I was just reading about how a lady drove down into the ravine here. 60′ fall and she climbed out with an ankle all busted up. I was trying to figure out how they could do that here. I thought there was plenty of parking.