A:TREK DURATION: 18 to 21 days
PROS: This jagged, humpbacked 22,840-foot peak is the tallest mountain in the Western and Southern hemispheres—or anywhere else outside of Asia. Yet, if you follow the popular Normal Route on the north side, you can make the long slog to the top without using the crampons and ropes you should pack.
CONS: On the frigid summit, the weather can change at any moment—and the strong winds can be brutal. When you’re climbing well above 20,000 feet, the sense of vulnerability and exposure is almost as strong as the ultraviolet rays beating down on you through the thin, dry air.
SUCCESS RATE: No concrete records are kept, but the average seems to be around 50 percent of climbers reaching the summit.
GUIDE SERVICE: Mountain Guides International has been leading climbers to the top of Aconcagua with relatively high success for more than two decades. Its 20-day trips limit the number of guests to six to eight people, accompanied by two guides. Price: $4,400.
THE CHOICE: Aconcagua. Despite all the reasons to climb Kilimanjaro—its scenery, its beauty, a chance to see the famed snows frosting its summit before global warming melts them—there’s something about some day being able to brag to your grandkids (and yourself) that you climbed a 22,000-foot-plus mountain peak. Aconcagua takes nearly two weeks more time to climb, so it’s definitely a much bigger time investment, and the weather conditions definitely can get more extreme. But the payoff of peering down at the surrounding, 20,000-foot peaks of the Andes makes it all worth it.