Hawaiian Trail & Mountain Corp.


Ka’au Crater

4.7 miles / Ridge, Steep-valley / Advanced


Lush vegetation, a swimming hole, waterfalls, a fascinating crater, and a superb open ridge walk along the Ko’olau summit, featuring outstanding views of Honolulu and Windward O’ahu. Use extra caution on the steep, badly eroded east rim.


  • Start at the ribbons and follow the stream mauka to the contour trail where we will turn right and head further into the valley.
  • Deep into the valley you will begin climbing on the side one of many waterfalls, crossing the stream several more times. Be very careful as the rocks are usually wet and very slippery. There are several sections with ropes, be very careful here.
  • At the top of the waterfall section, we will reach the rim of the crater where we will head to the right up ridge. Along the east rim of the crater there are some sections that are very steep and crumbly. Be careful if you use the ropes to keep from slipping.
  • There is a good break / lunch spot at the top of the east ridge, after which we will climb down to the west passing two utility towers before coming down the west rim back toward the valley.
  • After passing the towers on the makai side of the crater, we will take a ridge trail away from the crater back to the part of the stream where we started the hike.
  • Turn right when you reach the stream and follow the ribbons back to the trailhead.
  • Make sure you come out the same way we went in. If you exit the stream and hit the road inside the board of water supply fence, go back down to the stream and follow the ribbons makai to the trailhead. That is private property and we are not allowed to be hiking there.
  • For those who do not want to attempt the each rim, there is an option to take a shortcut by turning left instead of right at the top of the waterfall section. From there, head west to the tower and long the rim as far as you would like to go, before turning around and taking the ridge trail back.


  • Steep, slippery climbs up several waterfalls
  • Steep, eroded and sometimes narrow ridgelines along the crater rim
  • Sheer sections on both sides in some spots
  • A rusty, jagged utility pipe for the first 2 miles of the hike – be mindful of your feet and lower legs.
  • Leptospirosis may live in the stream, do not expose open cuts or wounds to the water.