Diamond Head State Monument

One of the best-known landmarks in the Pacific, Diamond Head is familiar to every visitor to O'ahu as the backdrop to Waikiki. The 228m (760ft) mountain is a tuff cone and crater formed by a violent steam explosion deep beneath the surface long after most of O'ahu's volcanic activity had stopped.

The crater is the site of Diamond Head State Monument, a visitor facility with picnic tables and a hiking trail up to the crater summit.

The trail to Diamond Head summit was built in 1910 to service the military observation stations located along the crater rim. Today it's a popular hike. Don't expect a walk in the park, as it's a fairly steep hike that takes about one hour return. For your efforts you're rewarded with a fantastic 360-degree view that takes in the southeastern coast to Koko Head and the leeward coast to Barbers Point, with Kapi'olani Park below.