Passage: The war was fought primarily in the Western Desert, which was about 390 kilometres (240 mi) long, from Mersa Matruh in Egypt, west to Gazala on the Libyan coast, along Via Balbia, the only paved road. The Sand Sea, 150 mi (240 km) inland, marked the southern limit of the desert at its widest at Giarabub and Siwa; in British parlance, Western Desert came to include eastern Cyrenaica in Libya. From the coast, extending into the hinterland lies a raised, flat plain of stony desert about 500 feet (150 m) above sea level, that runs 120–190 mi (200–300 km) in depth until the Sand Sea. The region is inhabited by a small number of Bedouin nomads, scorpions, vipers and flies.Bedouin tracks linked wells and the easier traversed ground; desert navigation was by sun, star, compass and "desert sense", good perception of the environment gained by experience. When Italian troops advanced into Egypt in September 1940,  the Maletti Group, lacking experience of desert conditions, got lost leaving Sidi Omar, disappeared and had to be found by aircraft. In spring and summer, days are miserably hot and nights very cold. The Sirocco (Gibleh or Ghibli), a hot desert wind, blows clouds of fine sand, which reduces visibility to a few yards and coats eyes, lungs, machinery, food and equipment; motor vehicles and aircraft need special oil and air filters and the barren ground means that water and food as well as military stores, have to be transported from outside.

Question: What is located in Mersa Matruh in Egypt?
The Sand Sea