Sheraton Caverns is a boat-accessed south-shore Kauai dive off Poipu built around collapsed lava tubes, archways, and partial overhangs. The site mixes roomy swim-throughs with sheltered reef structure, so it feels like a lava maze with clear route lines rather than an open reef. Turtles are a steady draw, and the caverns hold moray eels, octopus, crabs, shrimp, snappers, surgeonfish, triggerfish, and occasional sharks. It rewards calm buoyancy and good spacing because the overhead sections and boat-day traffic can make rushed diving feel cramped.