The ‘Aiea Loop Trail is 4.8-mile trail that begins and ends in the park. This trail runs along the ridge on the west side of Halawa Valley and offers views of the southern coastline of O‘ahu from Pearl Harbor (Pu‘uloa) and the Wai‘anae Range to Honolulu and Diamond Head (Le‘ahi).
Much of this area was replanted by foresters in the late 1920s. The lemon eucalyptus trees give the air a light citrus fragrance. Stands of Norfolk Island pine trees mark the lower end of the trail. Look for the native koa and ohi‘a trees as you reach Pu‘u Uau, the high point about midway along the length of the trail. You might also see remnants of a B-24 bomber that crashed in 1944.
This hike is not strenuous but involves some gradual uphill climbs with a steep switchback and a stream crossing at the end of the trail. The trail may be muddy with sections of exposed tree roots. Give yourself about 2.5 to 3 hours for the hike and enjoy the plants and the sound of birds around you.