Picture this as the world's biggest open-air aquarium. You go here to see fish, and fish you'll see. Due to their exposure to thousands of visitors every week, these fish are more like family pets than the skittish marine life you might expect. An old volcanic crater has created a haven from the waves where the coral has thrived. There's an educational center where you must watch a nine-minute video about the nature preserve before being allowed down to the bay. The bay is best early in the morning (around 7), before the crowds arrive; it can be difficult to park later in the day.

Snorkel equipment and lockers are available for rent, and there's an entry fee for nonresidents. Smoking is not allowed, and the beach is closed on Tuesday. Wednesday to Monday, the beach is open 6 am–6 pm (until 7 pm June–August). There's a tram from the parking lot to the beach, or you can walk the short distance on foot. Need transportation? Take TheBus each way from anywhere on the island. Alternatively, Hanauma Bay Snorkeling Excursions runs snorkeling tours to Hanauma Bay, with equipment and transportation from Waikiki hotels. Amenities: food and drink; lifeguards; parking (fee); showers; toilets. Best for: snorkeling; swimming.