Ridge A in the Australian Antarctic Territory. Apparently the advantage lies not so much with the absence of light pollution as with the quality of the atmosphere above the site:
At an elevation of 4,053 m, the ridge is not only remote but extremely cold and dry. The study revealed that Ridge A has an average winter temperature of -70 °C, and that the water content of the entire atmosphere in a vertical column above the ridge is equivalent to a layer of liquid water less than the thickness of a human hair.
The ridge is also extremely calm, which means that there is very little of the atmospheric turbulence elsewhere that makes stars appear to twinkle. "It's so calm that there's almost no wind or weather there at all," says Dr. Will Saunders of the Anglo-Australian Observatory and visiting professor to the University of New South Wales, who led the study.
"The astronomical images taken at Ridge A should be at least three times sharper than at the best sites currently used by astronomers," says Dr. Saunders. "Because the sky there is so much darker and drier, it means that a modestly-sized telescope there would be as powerful as the largest telescopes anywhere else on earth."