Spread across roughly 90,000 km² of the Indian Ocean but holding only 298 km² of land, the Maldives is an island nation southwest of India and Sri Lanka made up of about 1,190 coral islands grouped into 26 atolls. The atolls sit in a double chain on a submarine ridge and stretch about 750 km from Ihavandhippolhu in the north to Addu, just south of the equator, falling into northern, central and southern groups separated by deep channels called kandu. There are no hills and no rivers: islands average 1 to 1.5 m above sea level, and the highest natural point, on Vilingili in Addu Atoll, is about 2.4 m, the lowest high point of any country. Fresh water comes from rain and from thin lenses of groundwater floating on seawater inside the coral sand. The 2022 census counted 515,132 people, about two-fifths of them in the capital, Malé. Travelling the chain atoll by atoll shows how varied that flat geography is.
Ihavandhippolhu and the Northern Edge at Maliku Kandu
The country begins at Ihavandhippolhu, a small natural atoll 22 km long with 25 islands set around its rim and one long barrier reef along its western side. Its lagoon is 35 to 55 m deep and scattered with coral patches. To the north lies the broad Maliku Kandu, or Māmalē Kandu, the channel that separates the Maldives from the Indian islands of Lakshadweep, the nearest foreign territory.
Every island here, as everywhere in the Maldives, is coralline. The word "atoll" itself comes from the Dhivehi atholhu and is now used in languages worldwide. For ships the atolls were long a menace; the first accurate charts were drawn only in 1834 to 1836 by the British captain Robert Moresby, and Maldivian pilots still preferred his Admiralty charts until the 1990s. Two passages near the southern end of the chain were the only ones safe enough for ships crossing the ocean.
Thiladhunmathi and Miladhunmadulu, One Giant Atoll
South of Ihavandhippolhu the eastern and western chains open into Thiladhunmathi, which with its southern half, Miladhunmadulu, forms the largest atoll of the Maldives and the largest in the world if the mostly submerged Great Chagos and Saya de Malha banks are set aside. The northern part runs 76 km to the south-southwest with nearly forty fair-sized islands; Miladhunmadulu adds another 81 km and 101 islands. Today the single natural atoll is split among four administrative atolls: Haa Alif, Haa Dhaalu, Shaviyani and Noonu.
This is a very open atoll without a clearly bounded lagoon. Its western side has few islands and many isolated ring-shaped reefs, the faru, with wide passages between them; the German diver and naturalist Hans Hass observed how Porites corals build such micro-atolls here. Lagoon depths are typically 33 to 46 m. The pattern repeats down the northern Maldives: a rim broken into faru, many small islands, and deep sandy water within.
Baa Atoll, Faadhippolhu and the Manta Rays of Hanifaru
On the western side of the chain, Baa Atoll shows the northern atoll pattern in close-up. The administrative atoll, made up of southern Maalhosmadulu and two smaller natural atolls, measures about 46 km by 38 km and covers 1,127 km² of sea, yet its 105 reefs carry only 61 vegetated islands, half of them smaller than 10 hectares. The biggest, Dharavandhoo, covers just 45.5 hectares. Thirteen islands are inhabited, with over 11,000 people, and several more are resorts.
Baa's value is underwater. UNESCO designated it a biosphere reserve in June 2011, covering about 139,700 hectares of reef, lagoon and coast. Within it lies Hanifaru Bay, a small inlet where the tide pushes plankton into a dead end; it regularly draws some of the largest gatherings of manta rays anywhere, with up to a hundred individuals at once, and whale sharks, most of them young males, visit too.
Faadhippolhu, administratively Lhaviyani, lies across the inner sea to the northeast. Aerial views of it explain the national landscape better than any map: islands are only the highest patches of much larger reef platforms, built of sand and gravel piled up by waves, while uninhabited islands carry bushes, mangroves and coconut palms along the waterline.
North Malé Atoll: Malé, Hulhumalé and Thilafushi
North Malé Atoll is 58 km long, irregular in outline and holds about 50 islands, but it carries the country's weight. On its southern edge sits Malé, the old King's Island, where 211,908 people lived in 2022 on an administrative area of just 1.9 km², making it the most densely populated city in the world. The last Buddhist king converted to Islam in 1153 (some sources say 1193), and the 17th-century Hukuru Miskiy, or Friday Mosque, built of coral stone, survives in the city centre.
With no room left, the capital has manufactured land. Reclamation of Hulhumalé began on 16 October 1997 by pumping sand from the sea floor onto the Hulhulé–Farukolhufushi lagoon beside the airport island. The first residents moved in during 2004, a second phase finished in 2015 added 244 hectares, and by 2019 the island covered about 4 km², the fourth-largest in the country, and housed more than 50,000 people, with up to 240,000 planned. The project was planned partly as a response to the threat of rising seas. West of Malé, the lagoon of Thilafalhu was turned into Thilafushi, a landfill island that received its first load of the city's rubbish on 7 January 1992 and later gained industrial plots.
The same flatness makes the whole country vulnerable. When the Indian Ocean tsunami struck on 26 December 2004, only nine islands escaped flooding, fourteen had to be fully evacuated and six were destroyed. The lack of a continental shelf kept the waves to about 4.3 m at most, but the damage still came to an estimated 62 percent of GDP.
Ari to Laamu: the Central Atolls
South and west of Malé lies the central group. Ari Atoll, the second-westernmost, is an oblong 89 km long and only 31 km wide, with about 50 small islands mostly along its eastern fringe and a lagoon 55 to 73 m deep studded with large coral heads. To the east, Felidhu (Vaavu) has only 10 islands despite its size, and the reefs of its western horn wrecked many ships on the route between Malé and the southern atolls; it also contains the easternmost point of the country.
The two rows of central atolls end at Kolhumadulu (Thaa), 51 km long, a typical atoll that differs from those of the Pacific only in its greater size. Just south lies Haddhunmathi (Laamu), regular in shape and 48 km long, with a muddy lagoon averaging 55 to 62 m deep and large islands along its eastern rim, including Gan, the largest island in the Maldives. Beyond it opens Huvadhu Kandu, also called the Suvadiva Channel, about 97 km wide and the broadest gap in the whole chain.
Huvadhu, the Atoll With the Most Islands
Across that channel lies Huvadhu, which holds the Guinness World Record as the atoll with the most islands, 255 in all, spread over about 2,900 to 3,150 km² depending on the measure. Only 38.5 km² of that is dry land. The atoll runs 79 km north to south, its rim reef almost continuous, with outer islands built of coral boulders on the ocean side and sand on the lagoon side. Its lagoon reaches 91 m, deeper on average than any other in the Maldives, and about 30 sandy islands rise in its centre. Since the 1970s it has been divided into Gaafu Alif and Gaafu Dhaalu.
Isolation gave Huvadhu its own history. Its chief at Thinadhoo had unusual self-government, including the right to fly his own flag. The 14th-century traveller Ibn Battuta noted that it was the one province where a millet-like grain was grown, and master carpenters from Huvadhu built Malé's Friday Mosque. South of the atoll, the Addu Kandu, about 49 km wide, separates it from the last two pieces of the country.
Fuvahmulah and Addu, South of the Equator
Fuvahmulah, alone in the Equatorial Channel, is an atoll that sealed itself. It was once a small ring of reef with an open lagoon inside; coral boulders closed the channel to the sea long ago, sediment filled the basin, and the lagoon lost its salt. The result is a single island whose interior is lower than its edges, with two small lakes, wetlands and taro fields. Because it stands higher than most islands, seawater penetrates its groundwater less, and it is the only island that grows oranges and pineapples.
The far south is also the wettest part of the chain: annual rainfall averages about 3,810 mm here against 2,540 mm in the north, most of it brought by the southwest monsoon between late April and October.
Addu Atoll, 21 km long, marks the southern end of the Maldives, with broad barrier reefs carrying large islands on its east and west sides around an island-free lagoon 37 to 46 m deep. Its western islands are joined by roads over the reef about 14 km long. In 1941 the Royal Navy built a secret fleet base here, and from 1957 Gan served as RAF Gan until British forces withdrew in the 1970s. Addu City is now the country's second urban area, and the natural high point of the Maldives is on its island of Vilingili. Beyond it there is only deep ocean, about 520 km of it, to Peros Banhos in the Chagos Archipelago. For how reefs like these grow into rings in the first place, see what an atoll is, and to see how Huvadhu and Thiladhunmathi rank globally, read our list of the largest atolls in the world.