The Kaau Crater Loop Trail trailhead starts at the end of Waiomao Road in Kaimuki. There is a small parking lot, enough for five cars, just past the Honolulu Diamond Sangha temple. This trail is recommended for moderate to experienced hikers only, and you should be prepared to abort the trip during times of heavy rains as the trail can become unsafe. Come prepared with proper hiking shoes, and plenty of water—plan for at least five, but probably closer to six hours to complete the loop and take in all of the sights along the way. Several tour groups take small groups along this trail and could be a good option for those wary of going alone or for the first time.