If you need a reminder of who would ultimately win a contest of man vs. nature, visiting Antarctica is a good place to contemplate which side needs the extra set of long underwear. No place on the planet is more extreme than Antarctica -- the coldest temperatures, the harshest environment, one of the driest deserts (some internal valleys haven't received measurable precipitation for two million years). There are no permanent human inhabitants of the barren continent and at most a few thousand scientists at remote stations, so all visitors must be completely self-sufficient. Of the 45,000 or so lucky adventurers who make it here each year, most come by highly specialized cruise ships across Drake's Bay from Argentina (Ushuaia) or flights from Chile (Punta Arena) for about $5,000, and a few pay upwards of $40,000 for expeditions to the South Pole. While less than 1% of Antarctica is ice-free (the ice makes up 60-70% of all the fresh water in the world), the landscape is stunning. Colonies of penguins and seals populate the Antarctic Peninsula and austere mountains and icebergs break up the desolation.