Panoramas from this 760-ft extinct volcanic peak, once used as a military fortification, extend from Waikiki and Honolulu in one direction and out to Koko Head in the other, with surfers and windsurfers scattered like confetti on the cresting waves below. This 360-degree perspective is a great orientation for first-time visitors. On a clear day you can even see the islands of Maui and Moloka'i if you look to your left. The ¾-mi trail starts at the crater floor, and although most guidebooks say there are 99 steps to the top, that's only true of the first flight -- there are four flights altogether! Bring a flashlight to help guide your way through a narrow tunnel and up a very dark flight of winding stairs. And take bottled water with you to ensure that you stay hydrated under the tropical sun. COST: $1.