Most of the grand beauty of Hawaii must be seen on foot by exploring the numerous ancient sites, beaches, botanical gardens, rainforests, ridgetops, valleys, and waterfalls of each island. Honolulu alone, is accessible to a number of trails. Such trails stemming from the southeast of Oahu themselves are: Makapuu Lighthouse Road, Koko Crater (Railroad Approach), Mariner's Ridge, and Makapuu Tom-Tom.
The Makapuu Tom-tom trail is not for those who are scared of heights. Acrophobic hikers may have serious problems with certain trail sections. But definitely the view is rewarding. There are awesome vistas all the way - some of the best, most colorful coastal views in the world! If you happened to try this trail out after reading this, you'll discover that this article is no exaggeration.
For people who are just looking for a fun climb, then the Koko Crater trail is for you. Anybody who can climb the stairs can accomplish this trail. It's a no-sweat approach (no matter what condition you're in) to a great 360 panoramic view from a tip of Oahu - deep blue ocean all around! The only warning I could give you is that this trail lacks significant overhead cover (foilage, trees, etc.) and can be hot without winds. Word of advice: bring the necessary hiking equipment as you face the natural elements out there!