Like it simple? Then get yourself to delightfully basic Little Cayman Island.

Why are we stopped?" I wonder aloud to the pilot, right in front of me। The prop plane is at a standstill at the edge of a road, waiting to finish its taxi to Little Cayman Island's understated "air terminal." I just make out an iguana from my window, soaking up rays on the asphalt. A few yards away, a road sign: "Iguanas have the right of way; drive slowly."

There are few places left on Earth where international travel comes to a full stop for a sunning reptile; the squiggle of an island known as Little Cayman, and its 60 or so residents, are determined to stay one of them। Smallest of the three Cayman Islands, Little Cayman lies a half-hour plane hop—and light years of development—away from Grand Cayman, notorious for its good-time resorts and its status as the world's fifth-largest banking center. Like its sister islands, Little Cayman's deservedly famous top attraction is the fringe of unspoiled reefs along the Cayman Trench, the deepest point in the Caribbean Sea—which, combined with truly pellucid waters, add up to some of the most spectacular diving in the world. Barely ten square miles, Little Cayman is, like the iguana, a relic of an earlier Caribbean, when flocks of frigatebirds and boobies roosted in swamps dense with mangroves, when conchs crowded the seafloor like coins crowd the Trevi Fountain. When air terminals did double or triple duty as post offices and tourism centers.

I circle the island's mostly unpaved ring road, the whole circuit taking maybe an hour। Brackish ponds inland—inland is barely a mile wide—including Tarpon Lake, which glints with the large, silver-plated fish. Along the shore, mile after mile of reefs, pooling water the shocking color of verdigris. Almost no trace of human presence the whole way round; shell-paved road, low-lying vegetation, vast sky, and that breath-catching water. Essence of Island.

We boat into some shallows, where conchs still crowd the seafloor thanks to strict marine conservation laws. Slipping into the warm water, we snorkel for the mature conchs, gathering five in fewer than ten minutes. Sitting on the boat, feet in the water, waves lapping the reef, chewing seconds-from-the-water seafood with the sun a gold sand dollar above, it takes me maybe 50 seconds to promise myself I'll be moving here, soon, for the rest of my life.