جبال الحجر
The valley or wadi of Sama'il, also referred to as the "Sumail Gap", divides Al Hajar Mountains into the Eastern and Western subranges. A route from the coast to the country's interior traverses the valley. The gap extends about from the coast and Muscat Airport on one hand to Sama'il on the other. The route ends at Izki, and acts as the main road from Muscat to Nizwa. The highest point in the gap is above above sea level.