Rock Climbing Hawaii
Of all the Hawaiian Islands, Oahu has the most documented climbable rock. Lead and top-rope climbing is pretty much limited to Mokule’ia and Makapu’u. There are boulders to climb all over the place. Oahu is also home to Hawaii’s only rock climbing gym called Volcanic Rock Gym.
UPDATE 7/30/2012: The state of Hawaii has officially closed the Mokuleia and Makapu’u crags. If you get caught climbing there, you could get a hefty fine. Learn more here.
UPDATE 3/8/2015: The Mokule’ia Crag has been reopened, but you must join the Hawaii Climbing Commission (HCC). This puts you under the HCC permit with the state and allows you to climb legally. Membership is free. You can sign up at www.hiclimb.org.