India, Oct. 23 -- Pangong Tso, Ladakh. You can whip out your phone and take pics and videos of this pristine, 134 km, land-locked river basin, 14,000 feet above sea level. But you won't be able to post anything until you reach the closest towns, a few hours away. It's not just because it's difficult to build telecom towers in the remote region, but also because 60% of the lake lies in China, with the eastern end in Tibet. The Line of Actual Control passes through it. Perhaps the perfect place to think about who you are when you're disconnected from the wired world.

Yellowstone National Park, USA. The US offers phone coverage in many of its parks (useful for stranded hikers and animal attacks). But Yellowstone is just too vast, 9,000 sqkm...