After entering the park, take the Crater Rim Drive to the Chain of Craters Road. Drive until you reach the Hilina Pali road intersection. A vague trail across the Chain of Craters road leads to your destination. Most people drive right by here without even knowing what they're missing. Enjoy, and BE CAREFUL around the edges!
To log the cache, please take a photo of the crater. You DO NOT need to be in the photo!