It's a world without walls, an endless, noisy darkness. With nothing but mosquito nets to ward off the shrieking, roaring wildlife, I have settled my three young children to bed on their first night in the Costa Rican jungle. The concept of an open panorama of steamy rainforest meets raging Pacific was hugely appealing from the security of our four-walled home thousands of miles from this black confusion of cries, thuds and growling. The bamboo-hewn bedrooms of our base for the next two weeks have storm shutters, but the living areas have no choice but to merge with the jungle beyond.
A vista of almond trees crowded with scarlet macaws and the surf of the ocean behind persuaded the grown-up tenants of Casa Bambu to leave the room exposed to the elements at night with the reward of a lilac and orange dawn signalling an end to our nocturnal terrors. As more experienced travellers will surely testify, a first night in the jungle is always the worst. By the time you watch the sun set for a second time, the deafening call of the howler monkey no longer conjures images of a furious lion in the bed next to you, but reminds you of the handsome family that swung through the garden's mango trees earlier that day. The dark-furred howlers were just one of the marauding gangs that crashed through the trees around our bamboo house, chucking star fruit and bananas at the noisier monkeys playing Frisbee in the garden below.
My three little primates greeted their hairier friends with excitement every day of our holiday and with increasing recognition, distinguishing easily between the spider, white-faced, howler and squirrel monkeys that visited us daily. Although our kids took to their temporary neighbours as if such diversity were commonplace, seeing four different species of monkey on one spot is extraordinary and one of the greatest attractions of Costa Rica's Osa Peninsula. On the South Pacific Coast of the country, the Osa is held to be the world's second most bio-diverse region and is protected accordingly by a government well aware that this "Rich Coast's" wealth no longer lies in the gold plundered in previous decades, but in its thriving trade in eco-tourism.
The new influx of "gringos" following in the wake of the gold-rushers tend to be environmental tourists mixed with backpackers and a good handful of surfers. While the latter group head for the waves lapping the palm-fringed volcanic beaches, the rest are drawn to the Osa's greatest asset: Corcovado National Park. With more species of plant and wildlife than anywhere outside the Amazon rainforest, the park is a huge draw for professional and amateur naturalists, but welcomes only the hardy, as its conservation status prohibits development of luxuries such as roads or electricity.
Intrepid visitors to Corcovado can expect to encounter crocodiles and bull sharks in rivers (to be crossed only at low tide) as well as the less life-threatening abundance of coati, jaguar, anteaters and monkeys. Carate, the setting-off point for deep jungle trekking, lies a thrilling, but chassis-rattling 33kms from the closest town of Puerto Jimenez. Thundering our way through rivers, past wild horses and cowboys herding oxen along dusty planes, we arrived in our battered hire car at the southernmost point at which to access Corcovado.
Standing on Carate's broad black beach we were tantalisingly close to the wonders of the national park. We watched as steam rose from dense palm forest stretching endlessly north along the surf-crashing coastline. But the sun was out in full force searing, blistering even in the earliest hours after dawn. Just a few degrees from the equator, the Osa Peninsula is a hostile environment for toddling fair-skinned Scots and prohibited for us any attempt to penetrate its national park by virtue of the day-long beach hike required before the jungle trek even begins.
However, just 14 bumpy kilometres back along the Puerto Jimenez road, Cabo Matapalo is a sort of overspill for wildlife tired of being studied and recorded by earnest academics. There, alongside a handful of private houses, eco-lodges and a couple of restaurants, sloths, puma, anteaters and hundreds of monkeys make their home. It was at Matapalo that we discovered Casa Bambu built by a friendly Texan couple who, 15 years ago, fell deeply in love with the Osa's primitive charm and have enjoyed the pura vida there ever since.
Their two-storey creation on stilts sits in a landscaped garden of fruit trees leading down to a safe, although slightly rocky, beach. The warm waters here were the setting for surf lessons for our elder two and their uncool mother whose backside-in-the-air technique was in stark contrast to their own born-on-a-board performance. From the safety of the sand their amused father looked on as he fished for breakfast, lunch and tea, with varying degrees of success. Some mornings he would set off, rod in hand, in the watery light of dawn, to meet a few locals fishing on the beach among dozens of pelicans and a carpet of hermit crabs. When variable prowess or bad luck shortened our supply of fresh fish for meals we could have lived off the land thanks to the abundance of fallen fruit littering our garden, but a short climb to Lapa Rios, a nearby luxurious eco-lodge, held the promise of fabulous fresh food prepared and elegantly presented. As gorgeous as the thatched bungalows at Lapa Rios surely are, we conceitedly considered it the cheat's version of jungle living and were happy to return to our bamboo refuge, its basic facilities and rationed solar power.
Despite its lack of walls, we had no dangerous encounters with wildlife at Casa Bambu. The deadly bushmaster snake made no appearance despite being native to those parts and the only insects that joined us indoors were the enormous grasshoppers that fluttered around our mosquito nets at night. As to what else visited in the hours of darkness we can only guess. Shadows that might have been bats or birds flapped intermittently around our room, scurrying noises were ignored, and after a couple of days the roar of the howler monkey became a welcome heralding of dawn and another day of jungle adventure.
The equatorial rhythm of night and day was a balance that we quickly adopted and found strangely energising. The children were in bed 15 minutes after night fell at 6pm with their parents occasionally following not long after. As alien as this felt initially to us northern types, the opportunity to wake refreshed at 5am for a morning swim is the aspect of Osa life most missed by our family since we tackled for the last time the 19km-drive back to Puerto Jimenez. First impressions of Jimenez bring to mind the Wild West of 100 years ago which, given its gold-mining roots, should come as no surprise.
Dusty streets populated by swing-door saloons, horses and roaming dogs offer a nod to modernity with a small internet café and a couple of supermercados. Throughout our stay at Matapalo the town served us well in a friendly, yet somehow lawless, kind of way and it was with regret that we made our way through it on our journey home. We were headed for the tiny airstrip overrun by cycling children and furnished with only a bus-shelter and vegetable scales as primitive check-in facilities. From there, small 12-seaters fly to the capital, San José, soaring above a seascape of pale emerald free-form pools; still, brown rivers snaking inland from the coast spilling over mangroves and rice fields.
The beauty of the country they were leaving behind was lost on the children, however, who were entranced by the complexities of the open cockpit in front of them. Sitting just inches from the pilot on a shuddering, roaring little plane was as thrilling for our three-, seven- and eight-year-olds as their close-up wildlife encounters had been on land and was the perfect end to a holiday which was undeniably the perfect blend of jungle and surf.
There are no direct flights between the UK and Costa Rica. British Airways (0870 850 9850; www.ba.com) flies from Heathrow via Miami. North American airlines such as Continental, American, Delta and US Airways fly via US hubs. Alternatively, you can fly via Madrid on Iberia (0870 609 0500; www.iberiaairlines.co.uk). From San Jose, Nature Air (001 800 235 9272; www.natureair.com), flies to Puerto Jimenez on the Osa Peninsula.
To reduce the impact on the environment, you can buy an "offset" from Climate Care (01865 207 000; www.climate care.org). The environmental cost of a return flight from London to Costa Rica, in economy class, is £18.70. The money is used to fund sustainable energy and reforestation projects.
Casa Bambu, Pan Dulce Beach, Osa Peninsula ( www.casabambu-beach-house-rentals.com). Doubles start at US$115 (£67) until 14 November (children under 12 cost $20/£12 per night). From 15 November-31 August doubles cost $155 (£91); children cost $25 (£15).
Costa Rica Tourism: www.visitcostarica.com
Latin American Travel Association: 020-8715 2913; www.lata.orgReuse content