Which is the largest country by area that has no permanent rivers?

Saudi Arabia is the largest country by area that has no permanent rivers. Its immense territory covers about 2.15 million square kilometres, much of it occupied by desert and semi-desert landscapes.

The kingdom does have many wadis, including broad channels that can carry torrents after rare heavy rains. Unlike permanent rivers, however, these waterways usually dry out between floods. Water instead comes from groundwater, springs, desalination plants and seasonal runoff. The Rub' al Khali, or Empty Quarter, is the world's largest contiguous sand desert and occupies much of the southeast.

Saudi Arabia covers roughly 80% of the Arabian Peninsula, making it the largest country in the Middle East. Its borders reach the Red Sea and Persian Gulf, but neither coast supplies a permanent river system across the interior. A common mix-up is to treat wadis as rivers: “wadi” generally refers to a valley or channel that may flow only temporarily, especially after rain.