Koko Head Hike: Oahu, Hawaii, USA. For Oahu hikes during your Hawaii vacation, have a look at the Koko Head hike! This railway hiking trail is a top travel bucket list item for hiking in Hawaii USA and things to do on Oahu on Hawaii vacation. This hike is easy to get to from Waikiki and Honolulu, and there's snorkeling nearby at Hanauma Bay. Outdoor travel destinations and activities for budget adventures! Put hiking gear and outfits to wear on the Hawaii packing list!