• The ridge trails are often the most challenging, but offer airplane-window views of the island. The Mauumae Ridge Trail, also known as Lanipo, is often called the "roller coaster workout" for good reasons as it leads visitors along the tip-top of the dense green mountainside, with a closeup view of the rest of Koolau Mountains and the entire south half of the island from Koko Crater to the Waianae Mountains.

• Another high journey for experienced hikers is the 5.5-mile haul up the Dupont Trail in the Waianae Range, which rises 4,000 feet and eventually reaches Mount Kaala, Oahu's highest peak.

Many of the marked trails in the tropical forests can become tough to navigate, but those looking for help can call on the Hawaiian Trail and Hiking Club, which takes groups to different trails on Saturday and Sundays with members who know the locations of the island's most breathtaking landmarks.

The club also works to get permits and permission from land owners to complete some trails not normally open to the public, said member and trail coordinator Steve Brown.

But Brown admits many hikers still wish they could go back in time and climb the Haiku Stairs, the challenging ascent to the summit of Pu'u Keahiakahoe built by the Navy during World War II for access to radio equipment.

"That's a really sore spot for a lot of hikers," Brown said.

If you go

NA ALE HELE: www.hawaiitrails.net. Maps, trailhead access points and trail descriptions for hikes throughout Hawaii, organized by island.

HAWAII'S HIKING TRAILS: www.backyardoahu.com. Maps, tips, recommendations, weather, discussion boards.

HAWAIIAN TRAIL AND HIKING CLUB: www.htmclub.org. This Oahu-based club leads different hikes every weekend and publishes a quarterly hiking schedule on its Web site noting which hikes are open to nonmembers. A $2 donation is requested for each nonmember, age 18 or over. Children under 18 must be accompanied by a responsible adult.