The best thing to do on Oahu is get in your rental car and take a day trip around the island. If you're only staying in Waikiki, you're missing so much. You've got to get to the leeward side to see how lush the island can get. It's gorgeous. And you can pick almost any spot to park your car, get out, and do some exploring.
It takes less than a day to go around the island easily.
Oceanfront at the Outrigger Waikiki Hotel
2335 Kalakaua Ave
Go in here to see all the photos of Duke Kahanamoku, Olympic swimmer, sheriff of Honolulu, and local icon. The photos are scattered throughout the bar. This place is usually noisy and crowded, but go in to see the photos if nothing else.
Resort area, S coast of Oahu island, Hawaii. Located in the SE section of Honolulu, near Diamond Head, its famous beach is lined with luxury hotels; it has water-sports facilities as well as an aquarium, a zoo, gardens, and the International Market Place.
While driving around the island, stop to see the lookout points. Down below us was a beach and surfers.
You can find not so busy beaches around the island, be adventurous.