Fena Lake (Reservoir) is the largest lake in the United States territory of Guam and it is a man made reservoir. It is located in the south of the island on the Ordnance Annex military installation, and is overlooked by the nearby peaks of Mounts Lamlam, Alifan and Jumullong Manglo. The lake's outflow is to the north-west, its waters eventually reaching the Pacific Ocean at Talofofo Bay.