The first person to cross the Antarctic alone and unassisted

That's what Colin O'Brady just did. He walked 921 miles in 53 days. And he was dragging a 375-pound sled all the way as well as all of his food. This is not his first extreme adventure. He has also skied to both the north and south pole and hiked to the highest point in every US state.

Antarctica is the coldest, highest and driest continent on Earth. The cold freezes all moisture, technically making the landscape a desert.