Admission is charged per person and sat in the mid-twenties for an adult around the time of writing, with lower rates for seniors, students and children, and discounts for kamaʻāina and military with ID. Children under a certain age go free. Treat every figure you read online, including this one, as indicative — verify on the day.
Buying ahead online is usually available and is worth doing on a public holiday or a big-swell weekend, when the entrance queue is real.
Getting up the valley without walking. A shuttle runs the paved road between the entrance area and the falls. Capacity is limited and it is not a scheduled service you can time a visit around, so ask at the ticket desk rather than assuming. For anyone using a wheelchair or pushing a buggy, the paved path is genuinely manageable in a way that very little else on this coast is.
What is included. Entry covers the gardens, the archaeological sites, the falls and the swim when it is open. Food and retail at the entrance are separate.