Diamond Head State Monument, off Diamond Head Rd. between Makapu‘u and 18th aves., encompasses a 761-foot-high volcanic crater. The name derives from the volcanic crystals that 19th-century sailors mistook for diamonds. The Hawaiian name is Lē‘ahi. A steep .8-mile trail from the crater floor to the summit rim affords a panoramic view of Waikīkī. The .75-mile Fort Ruger Pathway runs along the exterior slope of the monument and offers rest stops and picnic areas.
The walk to the summit includes a 99-step stairway and may be difficult for the physically impaired. Restrooms are available at the crater floor park. Allow 2 hours minimum for the hike. The park is busiest between 9 and noon. When the parking lot fills up, vehicle traffic may be turned away. Wear comfortable walking shoes and a hat. Drinking water is available at the trailhead, but bringing an additional supply is recommended.