How to Explore Cartagena's Secret Islands

Yesterday evening, I’d stood in Plaza de la Trinidad watching a free Zumba class draw dancers of every age into the street. The air had been thick with humidity, the sultry sound of salsa drifting from open windows. Now, the city noise has faded, swallowed by the slap of the hull against the bay.

For a few moments, the Caribbean is all glitter and open water. Then Tierra Bomba appears on the horizon: first an emerald smudge, then a tangle of mangroves and palms spilling towards the sea. Pelicans wheel overhead. A fisherman lifts his catch from a wooden skiff. Along the shoreline, sandy tracks disappear into villages hidden beneath almond trees where children play football beside grazing goats and women chat in doorways.

Fifteen minutes. That’s all it takes to cross from one of South America’s most-visited cities to an island with no paved roads, no scheduled boat service to the mainland — only private charters and hotel transfers — and a population of just 9,000 people. From the island, the city skyline is still visible, faintly sparkling across the bay. And yet Tierra Bomba feels entirely, improbably, elsewhere.

I’m staying at Blue Apple Beach, a converted home on the southern shore, built using local materials and traditional techniques. Its thatched palapas (open-sided dwellings) are filled with works by Colombian artists and furniture made by island carpenters. Portia Hart, its British-Trinidadian founder, arrived here in 2016 when Tierra Bomba was being bypassed almost entirely by Cartagena’s tourism economy.

“I saw an island that was invisible,” she says, setting down her coffee at a table that looks out directly onto the Caribbean. “It’s minutes from a city full of visitors and yet, nobody was coming. I thought, that can’t be right.” Portia built a beach club, then a hotel and even started a recycling programme, too.

The fact that Cartagena is close isn’t always an advantage — the city’s rubbish arrives here, too, washed in on the tide, glinting in the mangroves, accumulating in the kind of places nobody visits often enough to clear. Portia noticed that Tierra Bomba’s hospitality industry had no glass recycling infrastructure, so in 2018 she founded Green Apple Foundation, an independent non-profit that now runs Cartagena’s first glass-recycling programme. Bottles collected from across the city are ground into sand and turned into drinking glasses and candleholders by a local women’s cooperative before being sold to some of Colombia’s finest restaurants. To date, more than 450 tons of glass have been diverted from landfill. “In a funny way,” Portia says, “the mess that came from being so close to the city gave us the idea for something we’re now proud of.”

To understand the island beyond the beach club, I climb onto the back of a mototaxi driven by a man who introduces himself as El Poeta, and we set off along the dirt tracks that serve as Tierra Bomba’s roads. The island spans nearly eight square miles, and El Poeta has never left. We pass the village of Bocachica, where the 18th-century Castle of San Fernando still guards the mouth of the bay, its battlements trailing bougainvillea. We skirt the shore at Punta Arena, where ramshackle bars tumble towards the ocean, then head down a backstreet lined with little houses painted lemon and coral.

The city is visible almost the entire time, glinting on the horizon. “People ask me if I want to live over there,” El Poeta says, jerking his chin towards the skyline. “I say: why? Everything I love is right here.” We slow for a dog in the road and I notice a scattering of bottles and plastic bags in the bushes — the city, again, sending its calling card. But for long stretches there’s nothing but mangrove-fringed, undeveloped coastline and the sense of a place that’s never been in a hurry.

A few days later, I board a boat for the 45-minute crossing to Isla Barú, and the city retreats a little further. Strictly speaking, Barú isn’t quite an island — the Spanish severed it from the mainland in the 16th century when they cut the Canal del Dique, and a bridge reopened the connection in 2014. You can, if you choose, drive here from Cartagena in an hour, but the roads quickly deteriorate into dirt tracks. The electricity, I’m told, comes on after dusk and shuts off at dawn. The town of Barú is a former palenque — a settlement founded by people who’d escaped enslavement in Cartagena and built a fortified, self-governing community beyond colonial reach.

My lodging for the next two days is Agua Barú, a collection of casitas staggered up a forested hill overlooking the boat-scattered bay of Cholón, where mangroves edge the water and herons pick through the shallows. At dawn, when the island still belongs to the birds, I snorkel in the protected waters of the Rosario and San Bernardo Corals National Natural Park. The reef below me is another world: parrotfish nosing through staghorn coral, a ray drifting across pale sand, a shoal of sergeant majors flickering like a handful of coins tossed into a fountain.

At Playa Blanca, the island’s most famous beach, day-trippers and vendors descend, but by late afternoon they’re gone. The beach empties, the water stills and the bioluminescent plankton — that ghostly blue glimmer stirred up by every movement in the shallows — makes nighttime swimming feel faintly magical. “This is what people don’t realise,” says my guide, Camilo, as we wade out into the dark water and watch our arms trail light. “Visitors come for the day and they have no idea what happens after sunset.”

On my final morning, I take a yacht further out still, into the Rosario Islands — 27 in total, scattered across a protected marine park to the south west of Cartagena. The city has disappeared entirely now. There’s nothing on the horizon but water and the faint green thumbprints of islands, some barely large enough to hold a palm tree. The sea changes colour as we go: jade, then turquoise, then a deep, improbable blue.

At Isla Grande, the largest island in the archipelago, we drop anchor to swim in water so clear we can count the fish darting beneath the hull. Canoes appear from the shore selling cold drinks, and a fisherman holds up a freshly caught lobster with an expression of pure pride. Then the engine starts again and we drift on: through Caño Ratón, a mangrove-fringed canal where rays glide along the sandy bottom in the green half-light and out to Isla Arena, a sliver of cream-coloured sand that barely breaks the surface of the sea. We have it to ourselves, nothing but open ocean and the soft collapse of waves on sand.

“I’ve been running boat trips out here for 15 years,” says our captain, Rodrigo, cutting the engine and letting us drift. “Cartagena locals all know these islands are here, but ask them the last time they came out,” he smiles. “They always look a little guilty.”

On the crossing back, the city re-materialises slowly, first as a shimmer, then as a skyline, then as the full clatter and colour of Cartagena reasserting itself against the dock. It feels slightly surreal for a moment: all of that out there, all of this here, and only a strip of water between them. Fifteen minutes to Tierra Bomba, 45 to Barú, an hour or so to the open ocean of the Rosarios. Not a great distance. But just far enough.