Sao tome and Principe: Prepare for turtle immersion

This West African island nation might be tiny, but it has acres of natural and cultural appeal, as Mike Unwin discovers during his visit to a unique retreat

Goooooooaal! It's another stunning strike from Ronaldo, arrowed into the top corner past the keeper's despairing dive. Or "Ronaldo" is, at least, what it says on the back of the shirt. But I have my suspicions: I can't see those signature golden boots – or, in fact, any footwear at all. Besides, this sandy strip of rubble and weeds is hardly the Bernabéu Stadium.

I'm standing in the terreiro – the central courtyard – of Roça Sundy, an abandoned 19th-century colonial plantation on the West African island of Príncipe. The teenage goalscorer is one of some 30 or so youngsters scattering chickens and dodging mango trees as they hurtle barefoot after the ball. A woman walks across the pitch, baby on back and firewood on head, while a single pig, in a clearly offside position, roots around near the opposition goalmouth.

These roças (pronounced "hossas", with a guttural "h") once formed self-contained little communities that were at the very heart of the former colony of São Tomé and Príncipe. Since 1975, however, when the Portuguese pulled out, many have fallen into disrepair, crumbling away as the jungle has crept back. Their dilapidated walls now house descendants of the worker communities that once lived outside them. Portuguese anthropologist Rita Alves leads me from room to room, accompanied by what is clearly her usual retinue of local children. She points out the old drying kilns for the cacao pods, the stables, the hospital and the overgrown railway track – a feature of every roça – built to transport produce down to the coast for export.

The grand house is still carefully preserved, its tables polished and walls hung with framed maps, part of a Unesco heritage project that embraces the whole island. As we look out from its verandas across the Gulf of Guinea, Rita explains how the first Portuguese settlers in the 1500s found the islands uninhabited. They proceeded to people them – at first, with slaves from the African mainland, destined for brutal transit across the Atlantic, and then, as the colony grew rich on sugar, coffee and cacao, with labour imported from Angola and Cape Verde. It was the descendants of these immigrant labourers who, in 1975, inherited the islands and proclaimed them an independent state – the second smallest in Africa, after the Seychelles.

Today, Roça Sundy seems to encapsulate this extraordinary history, the ruined grandeur of the islands' Portuguese past, buttressed with the tin-roofed lean-tos of their African present. Greenery from the surrounding forest spills over the fallen monuments of colonialism, as though impatient to reclaim the land. Straying from one cobbled pathway, I find children clambering over an ancient steam engine – now a museum-piece jungle gym. African grey parrots wing rapidly overhead and disappear into the forest, shrieking as they go.

The state of São Tomé and Príncipe lies in the Gulf of Guinea, some 300km off the coast of Gabon. Príncipe is the smaller and much the less populous of its two main islands, with around just 5 per cent of the total 188,000 population. It lies 200km north of São Tomé, where I'd flown in from Lisbon.

Arrival proved suitably dramatic: a 30-minute flight on a 15-seater, culminating in a Jurassic Park-style first glimpse of jungle-clad volcanoes below, then a final descent that took us directly over Bom Bom Island Resort, my home for the week. From the air, the resort's beaches, breakers, thatched chalets and wooden boardwalk snaking out to a tiny islet looked more than inviting.

Bom Bom belongs to venture capital firm HBD, the brainchild of billionaire South African entrepreneur, Mark Shuttleworth. Known to locals as the "man on the moon" for his space tourism exploits (he was the first African in space), Shuttleworth's aim has been more than simply to create an upmarket tropical retreat. HBD has a philanthropic mission to preserve Príncipe's unique heritage, both natural and cultural, and has sponsored numerous projects to these ends.

Rita is an HBD employee. Over the next week I meet several others. They include stonemason Manu Gomes, who is reviving traditional construction techniques to restore the roças and is passing his skills to local builders; and ecologist Estrela Matilde, who is educating schoolchildren about the island's natural resources and ensuring that HBD's own projects are sustainable. While Estrela and I chat by candlelight at Rosita's Place, a popular hangout in the tiny capital of Santo Antonio (which claims to be the world's smallest), friends appear with guitars and whip up an impromptu singsong. I'm told it's a traditional Príncipe ballad but the only word I can understand is "biosphera".

Bom Bom, meanwhile, turns out to be every bit as gorgeous at ground level as my tantalising aerial preview suggested – with the added satisfaction of knowing that it is the only such resort on the entire island. Think Caribbean idyll, but without the health spa, golf course or jet skis; just beach, jungle and the odd tiny fishing village.

Some come to Bom Bom for its celebrated big game fishing – now all catch-and-release. I opt for rather gentler activities, donning flippers and snorkel to explore the teeming reef, or strolling the grounds with binoculars to tick off some of the island's endemic birds – Príncipe golden weavers fashioning their hanging nests; the cobalt flash of a Príncipe kingfisher. At meal times, I tramp the boardwalk across to the island restaurant, where I dine on the likes of grilled silverfish and cajamanga mousse, helping myself to salads from an enormous giant clam shell while looking across to the resort's looming volcanic backdrop.

Short, bumpy vehicle excursions take me along red dirt roads to visit other attractions. At the impossibly picturesque fishing village of Praia do Abade I meet fishermen perched on their dugout piroques mending nets, while salted flying fish dry on their racks. At the Mirador Nova Estrela, I peer from steep cliffs to the volcanic outcrop of Jockey's Cap, encircled by dazzling white tropicbirds. And at Praia Grande, a two-kilo-metre sweep of sand, I marvel at the amphibious landing craft tracks of the huge sea turtles that hauled out from the waves the night before to lay their eggs by moonlight.

These turtles are big news. Bastien Loloum, an ecotourism consultant for marine conservation charity Marapa, tells me that these beaches are among West Africa's most important for breeding sea turtles. Whale watching is also excellent here, he explains, with humpbacks visiting inshore waters from May to October. And the island's proliferation of endemics – not only the birds, of which there are some 26 unique species, but everything from tree frogs to begonias – makes these islands "the Galapagos of Africa".

The best way to appreciate all this natural abundance is, of course, to ditch the vehicle and head out on foot – which is exactly what I do with my guide Carlos ("Cau") Marx. On my final morning, we leave Bom Bom after breakfast and head east around the coast, scrambling over the headlands from beach to beach. The loose soil of the forest slopes is undermined by the diggings of the enormous land crabs that venture out after dark, the vegetation a curious blend of the genuinely wild and the once cultivated gone wild. Thus, among the buttress roots and lianas of what feels like virgin rainforest, Cau points out the swollen pods of cacao trees, the tendrils of pepper plants and the over-ripe stench of fallen jackfruit, over which ants and butterflies swarm.

Carlos was born on Príncipe and knows these forests intimately. He demonstrates – with a splash from his water bottle – how to crush the leaves of one shrub into a frothy soap, and quenches our hunger pangs with various wild fruits. His eagle eyes also spy the powder-blue eggs of a maroon pigeon in their untidy cradle of twigs and the slender emerald coils of a São Tomé green snake slipping away into the vines. Both endemics, of course.

Our hike ends on Praia Banana, the most picture-perfect crescent of beach any brochure could envisage, where we wash off the sweat of the walk with a swim in the bay. Cau surfaces with an octopus wrapped decorously around one wrist. The indignant vermillion cephalopod shoots out a cloud of black ink, bunches its tentacles and jets off backwards into the depths.

My final night sees me back on Praia Grande in search of those turtles. But our timing is out. The full moon and low tide are both disincentives to any egg-bound females planning to come ashore. We take a walk anyway, tramping the length of the beach and slumping down to watch an enormous moon rising through the coconut palms.

I am still lost in the magic of the moment as we turn for home. So lost, in fact, that I don't immediately register my companions pointing excitedly at the sand. A fine stippling reveals where a clutch of green turtle eggs has hatched moments earlier. Infuriatingly, it seems we've just missed the exodus of hatchlings. But then Cau emerges into the torchlight, holding up a single flipper-flailing straggler between thumb and forefinger. We admire this exquisite little creature for a minute then return it to the sand. It scrambles down the runway of our torch beams and is swallowed by the surf.

Getting there

Mike Unwin travelled to Bom Bom in Príncipe and Omali Lodge in São Tomé with Rainbow Tours (020 7666 1250; rainbowtours.co.uk), which offers a nine-day holiday to São Tomé and Príncipe from £1,970pp. The price includes return flights from London via Lisbon to São Tomé with TAP Portugal, five nights' full board at Bom Bom in a pool-facing room and two nights' half board at Omali Lodge in São Tomé in a classic room, as well as transfers and internal flights.