Isla Fuerte is the least known and lesser visited of Colombia’s Caribbean islands, perhaps because of its location off the coast of Cordoba, 200 kilometers north of the main tourist hotspots of Cartagena and the Rosario Isles. Not that it is particularly hard to get to. In fact the 11-kilometer voyage from the mainland by small open boat takes 45 minutes, depending on sea conditions. Mornings are usually calm, but the afternoon swell can send the occasional wave washing over the bows. Landlubbers are advised to take the early boat.

The egg-shaped island covers just three square kilometers but is surrounded by coral reefs and ticks many other boxes for Caribbean idyll: palm trees waving in a soft ocean breeze, sandy beaches, clear water, happy locals in small boats, grilled lobster, cold beers, and a cave where ubiquitous Welsh pirate Henry Morgan hid some treasure.

What Isla Fuerte lacks is mass tourism, which means during off-peak times you have a good chance to get the whole beach to yourself and can lie back in your hammock with a cold beer imagining you are Richard Branson.

It also has an unexpected highlight in the form of two exceptional trees, as I am about to find out on a foot tour (there are no cars on the island) with our guide and hotel owner Horacio, a dentist from Medellín who first settled on Isla Fuerte back in 1976.

The first tree we visit, in a cow paddock in the center of the island, is a massive strangler fig known locally as El arbol que camina, or Walking Tree, for its ability to send down aerial roots from its branches and grow out horizontally. In this case the ficus, a single specimen but with a multitude of sinewy trunks, covers an astonishing 1,000 square meters with a lush green canopy.

Look closely though and something unsettling is going on. The fig finds its feet by enveloping other trees in a dense, woody latticework, like some creature dreamed up by H.R. Giger with branch-hugging tendrils and twisted roots erupting from the bowl of a slowly dying host tree. A kind of slow-mo botanical Alien. Its dappled shade is no place to linger.

The next tree we visit, just a 10-minute stroll from the creepy clutches of the strangler fig, is an immense bonga, which stands tall and proud on the highest point of the island. I have seen many of these large trees during my travels, but none quite like this with a four-meter-diameter trunk and foliage shading 2,000 square meters (the tree can be seen on Google Earth). I stand leaning against its grey trunk scanning the huge branches radiating from the crown above.

Ceibas are revered wherever they grow in the world and this one is no exception. Locals rest and chat in its shade, sitting on a gnarled root. Schoolkids use its lower branches as a hammock, lying four a time cradled in its protective arms. For the Afro-Colombian islanders, it is both the spiritual centerpiece and literal crossroads of the island; as it was, I imagine, for the Caribe people who inhabited this island in pre-Columbian times.

People in the village come to tell the tree their problems, said Horacio. “The tree has heard so many sad stories it cries.” And sure enough, high on the trunk is an eye-shaped whorl with a tear- drop in the corner. According to legend, the tree is estimated to be 2,500 years old and was enough of a feature 500 years ago to be recorded in the chronicles of Spanish conquistador Rodrigo de Bastidas, who sailed out in 1503 to explore west along the coast, discovering the River Magdalena and what we now know as Panama.

De Bastidas was a sympathetic conquistador for the modicum of respect he showed indigenous people. He had friendly dealings with those he met on Isla Fuerte, involved in salt production.

Later European arrivals were less welcome. In 1513, Francisco Pizarro, who would go on to ruthlessly conquer the Incas in Peru, tried to land to get water for his ships but was repelled by the islanders’ arrows, which might explain the islands name as “stronghold.” Pizarro’s miseries were aggravated when one of his ships was lost with all hands on a nearby reef and his own brigantine had its rudder swiped off by the “tail of a giant fish.”

The islanders’ resistance could be explained by the fact they had become the target for slavers. The Spanish crown originally made some effort to protect the New World natives from the depredations of conquistadors, and slaving was banned. But then came back stories of the cannibal practices of some Carib tribes. This shocked the regal powers. They had never come across anthropophagy before and, after consulting with the church, decided that human-flesh-eating natives needed to be enslaved to save their souls.

This of course meant conquistadors could accuse any tribe of cannibalism and enslave its members for profit. But in those days any gain was up for grabs, and the Spanish Main (as the tierra firme coastline of the Caribbean would be called) would be bitterly contested by other European powers vying for New World riches.

In a coconut grove in the middle of the island is a limestone cave where the 17th century buccaneer Sir Henry Morgan was supposed to have stashed some loot raided from some hapless Spanish treasure galleon along the coast. Anyone well travelled in the Caribbean knows that Morgan seems to have been here, there, and everywhere, leaving hidden treasure and a multitude of offspring in his wake. So Isla Fuerte has its own Morgan memento, a cave that extends 75 meters into the ground. Horacio doubts Morgan was ever really here, explaining that in this corner of the Caribbean, “Morgan is a general term used for any pirate … the same way we say Hoover for vacuum cleaners.”

This didn’t stop two treasure hunters moving to the island in the early 1900s to excavate in the cave after finding an old treasure map in their Bogotá attic. According to island legend, they spent the next 25 years digging until one day they mysteriously disappeared. “They went in the cave but never came out,” said Horacio, who relates this morbid detail only after I had myself crawled in and out of the dark hole. “Maybe they found the treasure and sneaked off in the night?” I suggest, hoping the story might have a happier ending. “More likely they fell into an underground abyss,” he said.

The whole story seems fishy, but after touring the isle by boat, I realize a similar lack of logic seems to infect modern-day bounty hunters, in the form of wealthy Bogotanos (mostly lawyers and architects, it seems) who have bought up most of the island’s coastline with empty beachfront mansions.

“The crazy thing is that after spending all that money most of them only visit two weeks a year. It doesn’t make sense,” rails our boat captain as we navigate reefs at the north end of the island.

The reefs, and the good diving they offer, are the main tourist attraction of Isla Fuerte. A scuba center on the island lures the day divers from the mainland. Back on the beach, a donkey brays, which is the cue for another comment from Horacio. “That donkey was born at 11 am,” he says, checking his watch. “Here on the island, don- keys bray every day at the exact hour they were born.”

I mentally struggle to digest donkey lore. “But surely a donkey brays many times a day, so there is a high chance it brays at the time, or close to the time, of its birth,” I suggest. “Yes, but they primarily bray at the time of their birth,” says Horacio. “It’s a fact.”

Lying in my hammock, watching the wafting palm fronds weave patterns against the night sky, I decide to give Horacio’s donkey theory the benefit of the doubt. Surely on this windswept isle where trees cry, caves swallow up treasure hunters, and giant fish beat back ships, I can believe donkeys bray to mark the hour of their birth. At least until someone proves otherwise on this small island of big wonders.

When to visit: Any time of year. January is high season and can get crowded. Two days on the island are more than enough. If you plan on diving, weekends are best as groups are present.

Getting there: Head to Lorica, Cordoba, and the last place with cash machines (in Olympica supermarket). Travellers can come via Monteria or Sincelejo. From Lorica get a local bus or share taxi to the fishing village of Paso Nuevo, about one hour from Lorica.

If driving, follow signs for San Bernado del Viento and Moñitos from Lorica. Paso Nuevo is approximately 20 kilometers after San Bernardo (ask locals for the crossroads as it is off the main road). In the village you’ll find places to park ($8,000 for 24 hours) within walking distance of the beach where fishing boats head to the island.

Boats go every few hours to the is- land and cost $15,000 per person, but locals will try and convince you to hire your own boat (for $150,000). Just hang out until a local boat is leaving and jump on and pay the passenger fee. Some boats have shade and lifejackets. Others don’t bother. The sea is calmer in the morning and the journey takes 30–45 minutes depending on size of boat and swells. The boat can drop you at the beach of your hotel or at the main dock at Puerto Limon, if you have nothing booked.

Where to stay: There is a hostel in Paso Nuevo and the accommodation is basic but clean. There are run- down hotels on the beach, eco-lodges, basic cabins, rooms to rent in Puerto Limon, and free camping on the west coast beach. Mar Abierto, owned by the Giraldos, has basic rooms and three simple meals a day for $150,000 pp. There are cheaper options. The upmarket Ecolodge and Dive center can accommodate up to 26 and, like La Playita Hostal (on Facebook), it has rooms for $45,000 per night including breakfast. Recommendation: stock up on bottled water you can buy from the hotels or in Puerto Limon.