Most of us think that Atacama is the driest places on Earth, but there are parts of Antarctica that have not experienced rain for two million years.
The unique conditions in the dry valleys of Antarctica are caused by so –called katabatic winds. These occur when cold, dense air is pulled downhill simply by force of gravity. The winds can reach speeds of 320kph evaporating all moisture, water, ice and snow--- in the process.
Though Antarctica is a desert, these completely dry parts of it are called, somewhat ironically, oases.
Lloyd, J., & Mitchinson, J. (2006). . New York: Harmony Books.
GeographyBlog. (n.d.). Retrieved May 6, 2015, from http://geog-ashu.blogspot.com/2010/04/driest-place-on-earth.html