Naval Base Subic Bay was a major ship-repair, supply, and rest and recreation facility of the Spanish Navy and subsequently the United States Navy located in Olongapo, Zambales, Philippines. The base was 262 square miles, about the size of Singapore. The Navy Exchange had the largest volume of sales of any exchange in the world, and the Naval Supply Depot handled the largest volume of fuel oil of any navy facility in the world. The naval base was the largest overseas military installation of the United States Armed Forces after Clark Air Base in Angeles City was closed in 1991. Following its closure in 1992, it was transformed into the Subic Bay Freeport Zone by the Philippine government.