Carcross Desert, located outside Carcross, Yukon, Canada, is often considered the smallest desert in the world. The Carcross Desert measures approximately 1 square mile or 640 acres. Not a true desert as the rainfall and humidity preclude this classification it is actually a series of sand dunes formed during the last glacial period. Glacial lakes were silted up and when the lakes dried up the sand dunes were left behind. Carcross is on the road going from Skagway to the Alaska Highway.