This 34 by 59 km sub-scene, acquired on July 5, 2000, covers the eastern part of the Strait of Gibraltar, separating Spain from Morocco. The promontory on the eastern side of the conspicuous Spanish port is the Rock of Gibraltar. The Rock of Gibraltar was once one of the two classical Pillars of Hercules, crowned with silver columns by Phoenician mariners to mark the limits of safe navigation for the ancient Mediterranean peoples. The rocky promontory still commands the western entrance to the Mediterranean Sea, separated from North Africa only by the narrow Strait of Gibraltar. A British colony, Gibraltar occupies a narrow strip of land at the southernmost tip of the Iberian Peninsula. It is separated from the Spanish mainland by a neutral zone contained on a narrow, sandy isthmus. The rocky limestone and shale ridge known as the Rock rises abruptly from the sea, to a maximum elevation of 426 meters (1,398 feet). Because of its strategic location and formidable topography, Gibraltar serves mainly as a British fortress. The Rock has traditionally been a symbol of British naval strength. Most of its sparse land is taken up by air and naval installations, and the civilian population is small.