Manoa Park: Giant Water Slides & Reef Snorkeling by the Ocean

Ditch the crowded city beaches for this massive water park right on the sand. You get two vibes: adrenaline-heavy slides and a massive wave pool, plus the chance to snorkel the Parrachos de Maracajaú reefs nearby. Buy the day pass early to secure a locker. Skip the overpriced snacks and hit the local tapioca stalls just outside. Four hours is plenty before the sun gets too intense. Don't forget reef-safe sunscreen.