Lake Khovsgol, Mongolia (no border)
Lake Khovsgol is the second largest freshwater reserve in Asia.
I camped by this awesome, remote and unpopulated lakeside for several nights during the spring of 2010, when the thick ice-sheet covering the surface was just beginning to break up and subside for the short summer. This was part of a 5-week mountain-bike expedition in the country. The spring weather was unsettled and made for some dramatic cloudscapes.
My only regret is not taking more panoramic shots like this! View Large On Black. What an incredible place!