Iran received its first delivery of Russian-made S-300 air defense systems in May, and it is getting ready to put them to use. Satellite imagery provided by AllSource Analysis shows intensive construction underway at an air defense base near Tehran to accommodate the systems. The layout of the new construction at the base appears to be notably different from those of existing air defense positions in Iran, and the base's location indicates that it may not be a permanent S-300 station, but a training facility. The base, near the east side of Tehran in the neighborhood of Afsariyeh, is surrounded by other military facilities. Among them are the barracks of the 65th Airborne Special Forces Brigade and the headquarters of the Islamic Revolutionary Guard Corps' cyber unit. The S-300, however, protects airspace up to 200 kilometers (124 miles) away.