Costa Rica | Central America | Riding tours | Riders in the storm

All of this is a roundabout way of saying that coming to Costa Rica makes you feel as though you could do things that seem absurd outside of a Saturday morning serial. I am standing on the beach at Baru, staring at the Pacific. In 10 days I will be standing on another beach staring at the Caribbean. There are 293 kilometres separating these two scenarios - every inch, coast to coast, covered with fecund jungle and vast plantations.

From here I'll head to Esquipulas via Plantanillo, then deeper through coffee country to Santa Maria. Over the Continental Divide is the Reventazon Valley, Mollejones and the Pacuare River for a tussle with class four rapids. What I'm going to attempt is cross-country in the most literal sense of the term - hiking, biking, rafting and kayaking the entire way. I'm joined by two guides and three other people: Alison from London, obsessed with sloths; her partner, James, who didn't look at the itinerary until a week ago and now has serious concerns; and a French-Canadian man who makes coffins for a living, a skill that might come in handy given one minor detail: I don't ride bikes. Or I didn't, until today.

Because right now the guides are telling us that weather conditions have knocked out almost all of the hiking sections. Their fingers roam across a map of Costa Rica, pointing out previously accessible areas and redefining them as my living nightmare. They're chilled in that Central American sort of way: no problem, everything is fine. But I'm importing Western stress levels and I would, at this very moment, like for a volcano to erupt and destroy the entire country. I had planned on sitting the cycling sections out, covering the others like a journalist at a tropical Tour de France. Now that the trip is mostly biking, this would mean skipping most of it.

But here's the other thing about Costa Rica: again, like a teenage fantasy, it makes you feel invulnerable. I find myself picking up a helmet and listening to instructions about changing gears, then wobbling off down the highway between trucks full of coconuts and cows. Just when I get the hang of asphalt, we veer left onto a dirt road. And when I get the hang of that, the hills begin - punishing, loose-gravel inclines that leave me pushing up the bike like Sisyphus and his giant stone. I reach the top, pause for a moment to stare at vultures circling overhead, then descend at breakneck speed into a monsoon. You half expect the next obstacle to be an earthquake, but that comes later, on day three.

When we arrive at the schoolhouse where we're scheduled to spend our first night camping, Alison peels off her waterlogged shoes and shrugs contentedly. "I don't know about you, but I really loved that," she says.

Shockingly, it turns out that I did, too. At my lowest point I dreamt of fluffy bathrobes and a Dyson hand dryer designed for the entire body. But you realise something very quickly when you're trying not to skid into a gruesome execution. The line between terror and exhilaration is very thin. People flock to horror movies for entertainment: the stakes may be higher crossing a country on your own steam, but the principle's the same. Safe from the storm, we all laugh deliriously.

After 43 kilometres my thighs, however, are murderous. And this is only day one, with nine more to go, each serving new challenges, a degustation of pain. We will, for example, pull off our shoes to wade through a rushing river where one slip would spell disaster. We'll cycle 11 kilometres up an excruciating hill to fried chicharrones and corn tamales. We'll endure mosquitoes, sunburn, flat tyres and truck drivers who drink tequila by the roadside at 10am. There are landslides and single-track trails so technical we'll carry our bikes over mud the colour of dried blood.

"When bathing in the rain was no longer one of the great pleasures of my existence, I knew I had left my childhood behind me," Aung San Suu Kyi once wrote. In Costa Rica, after days of rain, I'll renounce ever having been a child at all.

There's no question this adventure is aimed at the fit and hardy. But it's also one where every step from the comfort zone delivers spectacle and wonders: schoolgirls dancing on the road in Estrella surrounded by squashed guavas; a band playing in a lonely square of Londres. Sweat pours down your face and you look up to see Turrialba Volcano, belching smoke on the horizon. Toucans cheer you on when you need it most. A morning slog pushes you to the absolute brink, then you find yourself in a sugarcane field, drenched in the half-light of a dissipating storm, while the guide points out a ceiba tree and tells you that local natives once buried their dead at its base so souls could climb the sprawling branches to heaven.

In Santa Maria, I spend a free afternoon visiting the Cooperativa de Caficultores de Dota. This is a coffee co-operative that supplies a massive quantity of beans to Starbucks - in spite of that, perhaps, it has a reputation for being the best in the country. Visitors can tour the shelling factory and learn the intricacies that go into producing a single cup of joe. More than 800 farmers grow 2 million kilograms of beans a year here; the process has been perfected to produce ethanol and organic fertiliser. Cherries must be peeled, their seeds shelled and beans dried. Decaf is forbidden. "We don't do that in Costa Rica," the co-operative representative tells me.

These scattered glimpses of local agriculture - men lugging bananas, workers collecting palm oil seeds - stitch together to provide a satisfying picture of life in the tropics. Most travel is like a stone skipping over water, missing all the spaces in between; here you push headfirst into a rush of colour and smells, one place blending inextricably with the next until everything seems fluid and connected. You see, for example, how one action here causes a reaction there: how diminishing labour markets are slowly strangling villages such as Mollejones. We pull into town after an exhausting 62 kilometres of cycling, splitting up to stay with locals. I pass an evening with three teenage boys, watching overwrought soap operas while their mother, with exquisite hospitality, cooks gallo pinto and proudly shares her home. You see, at these moments, how you are connected too: cultural differences quickly fade away; your financial contribution has a heartening impact.

In Pacuare we swap helmets for paddles, the road for a furious river. Our final leg is also the most exhilarating. Pacuare River hosted the World Rafting Championships last year, so a week of physical endurance in the rain has provided good conditioning. Paddles go high in the air to form a group high-five. "Pura vida!" we yell, as half of the raft disappears beneath churning foam. Several hours later, the raft is upside down on a sandbar and our guide is making hors d'oeuvres.

When we reach the Caribbean, it is not what I expect. Howler monkeys are hooting us to the finish line. The monsoon continues unabated. We thrust forward (sea kayaks now) onto sand that is grey and covered in scattered debris. It's an image of the end of the world, parts of everything we've seen over the past 10 days broken and tangled in the waves. In a way it's perfect: after so much stimulation, colour and excess, what else could there be? Our minds are exhausted, depleted to a blank.

"Shall we turn around and do it again?" someone asks. I pop a cork and champagne splashes down my arms. Maybe a drink is in order first.

FAST FACTS

Getting there United Airlines has a fare to San Jose for about $2400 low-season return from Sydney, including tax. Sydney passengers fly non-stop to Los Angeles (13hr 30min) and then one stop to San Jose (about 7hr via Guatemala City); see united.com. Melbourne passengers pay about the same and transit in Sydney. As you are transiting in the US, Australians must apply for travel authorisation before departure at https://esta.cbp.dhs.gov.

Getting around World Expeditions offers the Costa Rica Traverse almost year-round, which it grades as "moderate to challenging". Accommodation, guides and most meals are included. Accommodation ranges from camping to comfortable hotels, with a home stay in Mollejones. Participants should be fit and well prepared, with sturdy hiking boots, a riding helmet and rain gear. Cost is $2690 a person. Phone 1300 720 000; see worldexpeditions.com.au.

Lance Richardson travelled courtesy of World Expeditions.