We stopped by on the way back from Hana. It's an interesting drive off the side road, especially when you have to drive through the river. Pay attention to the red poles.
Once inside, you drive for a while before parking. After that it's a self guided tour with a booklet. The Pi'ilanihale heiau was enormous. Each time you come around a corner and see it, you catch your breath. It's worth a visit, even at $10 a person. The bathroom is rudimentary, but works. There is no food of any kind there.
If you own or manage Kahanu Garden, register now for free tools to enhance your listing, attract new reviews, and respond to reviewers.