The capital city of Riyadh, with an estimated population of more than 2.5 million, lies within a wide east-west economic belt that crosses the Arabian Peninsula. The waist of the peninsula extends from the port city of Ad Dammam on the western shore of the Persian Gulf, westward to Riyadh, and then to Makkah (Mecca) and the Red Sea port city of Jiddah (Jeddah). This economic belt boasts one of the world’s most modern and highly effective internal transportation and communication networks. Riyadh, situated in an oasis, has served as the focal point for desert trade and travel for many years. The darker, linear features in this photograph are numerous highways and streets traversing Riyadh. Riyadh International Airport, with its V-shaped runways, is located north of the city. The meandering line of dark vegetation along the southwest side of the city is the Wadi (watercourse) Hanifah. This and similar photographs taken from space provide a great opportunity to measure and monitor growth of a rapidly expanding desert urban area with very little obscuring vegetation.