India, March 1 -- According to the purveyors of high-end travel, the new luxury is authentic and meaningful adventures, preferably as far from other humans as possible.

Ever since young men in the 17th century began taking what was known as the grand tour, a circumnavigation of Europe that could last for months or even years, we've been driven by an urge to discover new sights, experience new cultures and cuisines, meet people, hear strange tongues, undergo intellectual and spiritual enlightenment - and perhaps even enjoy the odd amorous adventure. In those days, journeying far from home was the preserve of a privileged few, a rite of passage for the extremely wealthy; indeed, it was only after the introduction of paid holidays in the la...