Aiea Loop Trail

ʻAiea Loop Trail is a 4.8-mile loop hike that starts and ends in Keaīwa Heiau State Recreation Area on Oʻahu, running along the west side of Halawa Valley’s ridge line.

The loop is designed for easy-to-moderate hiking effort: expect a forested route with gradual climbs, plus a few steeper switchback sections and a stream crossing near the end. Elevation gain is about 900 ft, and most hikers budget around 2.5–3 hours.

High point is Pu‘u Uau, reached about midway through the loop. As you move up and down the ridge, the vegetation changes—stands of Norfolk Island pine mark the lower portion, while koa and ‘ōhi‘a show up as you near Pu‘u Uau.

A major feature of the lower section is the ridge-and-valley alignment: the trail offers views of the southern coastline of Oʻahu (from Pearl Harbor / Pu‘uloa) toward the Wai‘anae Range, with visibility back toward Honolulu and Diamond Head (Le‘ahi).

Along the ridgeline you may also encounter remnants of a B-24 bomber crash from 1944, alongside other WWII-related traces described for this route.

Management and etiquette are straightforward: the loop begins at the upper eastern end of the park off the park road (parking lots, picnic pavilions, and restrooms), then finishes by coming out at the lower campgrounds and following the park road back to your car. Mountain biking is not allowed; dogs must be on leash; stay on the trail and pack out what you bring in.

More information: Hiking the ʻAiea Loop Trail on Oʻahu, Hawaiʻi, AIEA LOOP TRAIL | The Hiking HI, Division of State Parks | ʻAiea Loop Trail