BETWEEN 1960 AND 1984, visitors to Colombia's Isla Gorgona arrived shackled and blindfolded and slept behind barbed-wire fences, on wooden bunks without mattresses. The 2,500 inmates of Gorgona Prison were warned that, if they escaped, the venomous snakes on the tropical island would kill them and, if they braved the ocean, the sharks would get them instead.
Today, the lush, 6.5-square-mile island, 30 miles off Colombia's Pacific coast, is a national park; the lodging here has been managed since 2006 by the winner of the Colombian version of the TV show The Apprentice. Which is to say, this is one strange escape. I arrived last September via speedboat from the coastal town of Guapí. Upon touchdown, military police searched my bags for alcohol (it interferes with the requisite antivenin) and weapons. The other guests—the island hosts 130 at a time—were mostly schoolchildren and besotted couples, enjoying king-size beds in the updated guard quarters by the beach.
I spent my days exploring: first, the grisly ruins of the mammoth stone penitentiary, said to be modeled after a Nazi concentration camp and now overrun with capuchin monkeys and foot-long basilisk lizards, then the dense tropical jungle that covers 85 percent of Gorgona, for which the island provides obligatory boots. There really are pit vipers and coral snakes here, as well as easier-to-spot (and mostly harmless) boa constrictors.
The trekking's good and the kayaking better—I spent a few afternoons dipping into the equatorial water as blue-footed boobies and frigates flew overhead—but the main activity on Gorgona is diving. The island has a fully equipped dive center, and I'd regularly see 20 to 30 moray eels at any site, many as thick as my thighs. Gorgona's nature preserve extends to a six-mile radius around the island, so fish and turtles are plentiful, intrepid, and big. But size is relative. From July to September, humpbacks come to Gorgona's banks to mate and calve, and to see them breach and slap the surface with their gargantuan tails is to forget that once this was a place no one ever, ever wanted to go.
GET THERE: Three-night packages, including three meals daily, island transfers, and flights from Cali to the coastal town of Guapí, in the Cauca department, from $463 (concesionesparquesnaturales.com). Two-dive day trips from Gorgona's dive center, $90. Kayak rentals, $5 per hour.