The record of being the driest place on our planet clearly belongs to the 1,40,000 square kilometer Atacama desert in Chili, South America (see the map). It hasn’t experienced rainfall since last 450 years or so and it seems that the dry spell may have begun much earlier.
Atacama is the oldest desert. It was formed about 10 million years ago. Some of its areas are so hot and arid that even the hardiest bacteria are unable to survive in the hostile environment.
Atacama Desert (Wikipedia)