Malden Island, sometimes called Independence Island in the nineteenth century, is a low, arid, uninhabited island in the central Pacific Ocean, about 39 km2 (15 sq mi) in area. It is one of the Line Islands belonging to the Republic of Kiribati. The island is chiefly notable for its mysterious prehistoric ruins, its once-extensive deposits of phosphatic guano (exploited by Australian interests from c. 1860–1927), its former use as the site of the first British H-bomb tests (Operation Grapple, 1957), and its current importance as a protected area for breeding seabirds.