The island is chiefly notable for its ancient stone architecture, 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.

[1] In 2014 the Kiribati government established a 12-nautical-mile (14 mi; 22 km) fishing exclusion zone around each of the southern Line Islands (Caroline (commonly called Millennium), Flint, Vostok, Malden, and Starbuck).

A large, mostly shallow, irregularly shaped lagoon, containing a number of small islets, fills the east central part of the island.

Sixteen species of vascular plants have been recorded, of which nine are indigenous.The island is largely covered in stunted Sida fallax scrub, low herbs and grasses.

Introduced weeds, including the low-growing woody vine Tribulus cistoides, now dominate extensive open areas, providing increased cover for young sooty terns.

Two kinds of lizards, the mourning gecko (Lepidodactylus lugubris) and snake-eyed skink (Cryptoblepharus boutonii), are present on Malden, together with brown libellulid dragonfly.

[4] The earliest documented sighting of Malden Island by Europeans was on 25 March 1825, by Captain Samuel Bunker (1796–1874) of the whaler Alexander of Nantucket.

Bunker's journal for that day mentioned that "it proved to be an island seen by the Sarah Ann of London and the Independence of Nantucket, Capt.

Byron, commanding the British warship HMS Blonde, was returning to London from a special mission to Honolulu to repatriate the remains of the young king and queen of Hawaii, who had died of measles during a visit to Britain.

[8] Andrew Bloxam, naturalist of the Blonde, and James Macrae, a botanist travelling for the Royal Horticultural Society, joined in exploring the island and recorded their observations.

Writer Beatrice Grimshaw, a visitor to Malden in the guano-digging era, decried the "glaring barrenness of the bit island",[11] declaring that "...shade, coolness, refreshing fruit, pleasant sights and sounds: there are none.

She described Malden as containing "a little settlement fronted by a big wooden pier, and a desolate plain of low greyish-green herbage, relieved here and there by small bushes bearing insignificant yellow flowers".

Grimshaw described these edifices as being "large, bare, shady buildings fitted with wide shelves, on which the men spread their mats and pillows to sleep".

In 1956, the United Kingdom selected Malden as the "instrumentation site" for Operation Grapple its first series of thermonuclear (H-bomb) weapons tests, based at Kiritimati (Christmas Island).

[4] Multiple people were invited to observe these tests including future governor general and president of Fiji Ratu Sir Penaia Ganilau.

[19] The main value of the island to Kiribati lies in the resources of the 200-nautical-mile (230 mi; 370 km) exclusive economic zone which surrounds it, particularly the rich tuna fisheries.

Gypsum deposits on the island itself are extensive, but do not appear to be economically viable under foreseeable market conditions, mainly due to cost of transportation.

[3] Some revenue has been realized from ecotourism; the World Discoverer, an adventure cruise ship operated by Society Expeditions, visited the island once or twice annually for several years in the mid-1990s.

This sanctuary is administered by the Wildlife Conservation Unit of the Ministry of Line and Phoenix Islands Development, headquartered on Kiritimati.

[20][page needed] There is no resident staff at Malden, and occasional visits by foreign yachtsmen and fishermen cannot be monitored from Kiritimati.