“For the most intrepid tourists, creative companies are devising strenuous mind-body challenges—with a little make-believe mixed in.”

“IT’S BEEN 22 YEARS since Jon Krakauer’s account of conquering Mt. Everest, “Into Thin Air,” first introduced many travelers to the exhilarating highs and life-threatening lows of extreme travel. That thirst for the ultimate trek has not abated—last year, deadly human traffic jams on Everest prompted Nepali officials to institute new safety rules. But lately intrepid thrill-seekers and travel experts are seeking out daunting trips that satisfy that desire both safely and more originally.”