Jules' Undersea Lab in Key Largo, Florida

Sitting in a lagoon at MarineLab Undersea Park in Key Largo, this pressurized habitat is a compact world of portholes, bunks, and machinery with an uncanny feeling of domestic coziness. MarineLab describes it as the world’s only underwater habitat where recreational divers can experience living and sleeping underwater, and the broader organization traces the habitat’s story back to La Chalupa, an earlier undersea research station in the Caribbean. Over time, the habitat shifted roles from research station to hotel and now to an educational attraction operated by the nonprofit Marine Resources Development Foundation. A three-hour visit to the lab includes a guided dive through the lagoon and entry into the habitat itself. The overnight “Aquanaut Adventure” stretches the fantasy further with meals, free time inside, and the wonderfully absurd promise of hot pizza delivered underwater.