Rapids pinned the eight-man raft against a boulder, forcing those of us who weren't swept under water to scramble up the side of the 20-foot-high rock.

Rapids pinned the eight-man raft against a boulder, forcing those of us who weren't swept under water to scramble up the side of the 20-foot-high rock.

Once on top, it was clear there was no good way off. The Urubamba River was gushing pretty strongly, and the boulder was an island in the middle. So our guides set up a rope that we could use to yank ourselves through the current to the bank.

The guide who had anchored the rope had a more complicated escape: After freeing the raft from the boulder, he swung it around to the far side and jumped, making an uncertain landing on the vessel just as it was swept anew into the rapids. Downriver, he paddled to the side and reunited with us, those who had been swept away and our mates who had successfully snaked their rafts through the rapids.

This was 2002, and the beginning of my first adventure trip. When we kissed the boulder, I had barely learned the names of the nine others who had signed up for two weeks of rafting, hiking and mountain biking in Peru.

At the time, I was still wrestling with the nagging doubts: Could I handle the trip? Would I like the people? And what would happen if the answers were no? Would I be stuck in the middle of nowhere with no way out?

This was the tipping point. People could either unravel or bond after the near-tragedy on the river. We did the latter, thankful that no one suffered anything more than being a bit shaken up. Our survival became a point of humor, if not pride, as we continued on to hike to Machu Picchu and mountain bike through the hills.

Yes, we learned, this would be an adventure. Anything that did not go perfectly ultimately would add to the experience.

The lesson is one I've repeated (although with less drama) in the years since, as I've gone hiking, biking and kayaking in Mexico, Nepal, Tanzania and Venezuela.

I'm not exactly a thrill-seeker, I certainly don't qualify as an athlete and I didn't grow up on mountains, in rivers or in the Xtreme-sport subcultures that require Xtravagant spelling to show how Xciting life can be.

But even I can go places completely outside my normal life, places where the natural world still has power to amaze. You can too.

Before Peru, I conjured all kinds of possible pitfalls about the trip, many of them dealing with whether I would fit in.

Would the others be a bunch of musclemen or adrenaline junkies on a quest to prove who was king of the mountain? Alternatively, what if I was the jerk store grumbling about the slowpokes?

I've found neither problem in real life. People just go at different paces and regroup as needed.

Pinning down what type of person goes on these trips is harder than you'd think.

In Peru, the group ranged from a 29-year-old attorney from Minneapolis to a 59-year-old petrol-station owner from England. My oldest traveling companion ever was a retired carpenter, age 84, who was part of my trip through Venezuela in November. He was accompanied by his 74-year-old wife, both of whom made a difficult climb despite a taxing cold.

Several of my travel mates have run, cycled or snowboarded regularly at home, but most of them look like your neighbors. None were freaks of nature. I'd estimate that my groups have skewed slightly male, maybe by a 60-40 ratio.

My only example of a failed traveler was 34 years old, from Chicago, and clearly had not given any thought to what a trek would be like. I think what sent her over the edge was the realization that camping meant going to the bathroom in a tent.

So she never saw Roraima, a flat-topped sandstone mountain in Venezuela that boasts one of the most bizarre universes I've seen.

Little lives atop the tepui (it's 9,200 feet at the highest point), and Roraima is often cloud-covered, so there's a cotton-ball mist that envelopes its rock formations. All the moisture leaves a dark green, almost black moss that covers virtually everything but the boot-scraped paths that trekkers leave behind.

And yet, startling splashes of color appear where rare orchids have found a home. Tiny black frogs, miniature tarantulas and butterflies are about the only life forms that aren't carrying backpacks. And them-thar clouds also hide surprises like the natural rock structure I dubbed "the Parthenon" for its columns and classical shape.

The quitter rejoined the other 14 of us for the other parts of the Venezuela trip: visits to the world's tallest waterfall (3,230-foot Angel Falls) and the Caribbean waters of the Los Roques archipelago.

She didn't pay the physical price to climb Roraima, which included rain - lots of it - and a pretty vertical hike to the top. She wasn't there when we all huddled in a tiny hut waiting for a downpour to slow just enough so we could set up tents in the mud. She missed the scramble up wet rocks through the twin waterfalls crying from Roraima's face.

In short, she missed all the best parts.

At the end of our two weeks in Venezuela, the Chicago woman listened as we all talked about the trip. The whole conversation was about Roraima. That's when we bonded over the joint miseries and delights of the land. That's where the inside jokes were born, and where we learned about one another.

The worst parts were wrapped together with the best ones.

Prices for adventure-travel trips can vary widely - the two- to three-week treks I've taken are priced at $3,000 or less, but others easily exceed $5,000. The price tag seems to depend mostly on the location, how cushy the accommodations are and the length and type of activity.

Be forewarned that international flights typically aren't included in the price and that you'll probably be shelling out something for gear before you leave town.

But whatever you pay, the good news is there's little need for money once you're on a trek, unless you're buying lots of gifts and/or alcohol. And in most cases, the local handicrafts and drinks aren't that expensive. It's not like going to Paris.

I suppose my travel mates must have bought things during our three-week Annapurna Circuit trek in 2006, but I don't remember those or even what was being sold.

My memories of the trip to Nepal are of the transformations as we ascended to and through a pass about 17,765 feet high in the Himalayas.

Days earlier, we were wearing shorts and sweating as we tromped past the most verdant fields I've ever seen. We moved out of those terraced hillsides through endlessly changing environments - forests, ranchland, rock-mining areas and more - until we had climbed into snow-covered territory where even the hardiest brush abandoned efforts to grow.

By the time we reached our base camp below the Thorung La pass, a third of the group was suffering food poisoning. How they ever dragged themselves the last stretch, I'll never know. But after a day of rest, they were ready for the trek's big, 12-hour day.

We woke early that morning, tossed on our warmest layers of clothing, fed ourselves and began the tedious trudge to the pass. Our pace was not unlike that of the Imperial walkers in The Empire Strikes Back (sorry, non-nerds) but we needed the early start to avoid the afternoon winds.

About five hours later, we had made the top, where a multitude of Buddhist prayer flags mark Thorung La. We celebrated and took the obligatory pictures, and then began our way down, down, down.

By the time we collapsed into our tents that night, the group was back into shirtsleeves. The ones who had been sick were particularly fatigued but also exhilarated by all they had achieved.

I'll bet they'll never forget that day and that the tough patch remains at the center of their Nepal story. Nothing quite captures the power and romance of the natural world like having to struggle to see it.

Just like my kiss in Peru.