The Islands of India Explained

The islands of India are the more than a thousand islands and islets scattered along its coasts and in its seas, led by the forested Andaman and Nicobar chain in the Bay of Bengal and the coral atolls of Lakshadweep in the Arabian Sea, together with hundreds of smaller river, estuarine and offshore islands. Although they make up only a tiny fraction of the country’s land area, they extend India’s maritime boundary far into the ocean and shelter some of its richest rainforests, coral reefs and indigenous cultures. Last reviewed: 4 November 2026.

Most people picture India as a solid triangle of land, yet it also has one of the most varied island portfolios in Asia. Some islands are the exposed tops of drowned mountains, others are volcanic cones, others are living reefs built by tiny animals, and still others are shifting sandbars in great rivers. This explainer sets out where India’s islands are, how they differ in origin, what lives on them, and why they matter for ecology, security and climate.

Quick Facts: The Islands of India at a Glance

Key Takeaways

• India has two major island territories, the Andaman and Nicobar Islands in the Bay of Bengal and Lakshadweep in the Arabian Sea, plus many smaller coastal, estuarine and river islands.
• The Andaman and Nicobar chain is a rugged, forested extension of a submerged mountain arc and includes India’s only active volcano, Barren Island.
• Lakshadweep is made of coral atolls on the Chagos-Laccadive ridge, so its islands are low, small and especially exposed to rising seas and coral bleaching.
• The islands extend India’s maritime reach and strongly increase its exclusive economic zone, which makes them important for fisheries, shipping and security.
• Several island communities, including the Jarawa, Onge, Shompen and Sentinelese in the Andaman and Nicobar group, remain among the world’s least contacted peoples and are legally protected.
• Climate change, tsunamis, cyclones, coastal erosion and large development projects are the main pressures on India’s islands.

What Are the Islands of India and Where Are They?

The islands of India are found in three main settings: two oceanic groups far from the mainland, a string of near-shore islands along the coast, and river and delta islands inland. Counting them depends on how small an island may be, but the commonly cited total runs well past a thousand.

The Andaman and Nicobar Islands lie roughly 1,200 kilometres off the east coast, stretching north to south across the Andaman Sea. Lakshadweep sits in the Arabian Sea, some 200 to 400 kilometres off the Kerala coast. Near the mainland are islands such as Elephanta and Salsette near Mumbai, Pamban near Rameswaram, Sriharikota on the Andhra coast, and the sandy islands of the Sundarbans. Inland are enormous river islands in the Brahmaputra and Ganga systems, such as Majuli in Assam.

Because they sit in such different environments, each group of islands behaves differently. Oceanic islands depend on the sea for almost everything, while river islands live and die by floods, silt and erosion.

What Are the Andaman and Nicobar Islands?

The Andaman and Nicobar Islands are an archipelago of roughly 570 islands and islets, a union territory of India that forms the exposed crest of a long submerged ridge running from Myanmar’s Arakan Yoma range south toward Sumatra. Only a small number of the islands are inhabited, and most remain covered by dense forest.

The group is split into the Andamans to the north and the Nicobars to the south by the Ten Degree Channel, a deep strait about 150 kilometres wide. The Andaman group is further divided into the North, Middle and South Andaman, Baratang, Little Andaman and several smaller islands. The largest of the Nicobar islands is Great Nicobar, whose southern tip at Indira Point is the southernmost land of India. The capital, Port Blair on South Andaman, has been renamed Sri Vijaya Puram in recent official usage.

The land area is only about 8,000 square kilometres, yet the territory commands a vast stretch of ocean and a position near the Strait of Malacca, one of the busiest shipping routes on Earth.

How Did the Andaman and Nicobar Islands Form?

The Andaman and Nicobar Islands formed through plate tectonics, where the Indian plate dives beneath the Burma microplate and pushes up a chain of folded and faulted ridges, some topped by volcanic cones. They are therefore the high points of a submerged mountain range rather than coral or purely volcanic islands.

The rocks include sedimentary sandstone and shale, ancient ophiolites (pieces of ocean crust thrust up onto land) and limestone, with a fringe of living coral reef around many shores. This subduction zone is the same system that generated the huge 2004 Sumatra-Andaman earthquake and the Indian Ocean tsunami, which raised some islands and sank others by a metre or more in places.

Two volcanic islands stand out. Barren Island, east of Port Blair, is India’s only confirmed active volcano and has erupted intermittently in recent decades, producing ash plumes and lava flows. Narcondam, farther north-east, is a dormant volcano and the home of the endemic Narcondam hornbill. Both are tiny uninhabited peaks rising from deep water.

What Is Special About the Ecology of the Andaman and Nicobar Islands?

The islands are special because their isolation has produced dense tropical rainforest, mangroves and coral reefs with an unusually high share of endemic plants and animals. A large proportion of the territory is still forested, and the forests rank among the most intact in the country.

The vegetation ranges from evergreen and semi-evergreen rainforest to moist deciduous forest, with towering padauk and gurjan trees, plus extensive mangrove belts and beach forests. Endemic wildlife includes the Nicobar megapode, the Andaman wild pig, the Nicobar tree shrew and the Narcondam hornbill. The surrounding seas hold fringing coral reefs, seagrass beds and nesting beaches for sea turtles, including the leatherback, and the salt-water crocodile hunts in creeks and estuaries.

Several national parks and sanctuaries protect these habitats, and the Great Nicobar Biosphere Reserve is part of UNESCO’s international network of biosphere reserves. Their long isolation, however, also makes native species vulnerable to introduced animals such as spotted deer and rats, which were brought to the islands in the past and now damage the forest.

Who Lives on the Andaman and Nicobar Islands?

The islands are home to several Indigenous peoples, including the Great Andamanese, Jarawa, Onge and Sentinelese in the Andamans, and the Nicobarese and Shompen in the Nicobars, alongside settlers from the mainland. Some of these groups are among the last communities in the world living largely by hunting, gathering and fishing.

The Sentinelese of North Sentinel Island reject outside contact entirely, and Indian law keeps outsiders away from their island and a wide zone around it. The Jarawa live in a reserve along the western side of South and Middle Andaman, with a long-running debate over the road that crosses their forest and the effects of tourism. The Shompen of Great Nicobar are a small, semi-nomadic forest people. Many of these groups were devastated by disease and outside contact in the colonial era and remain extremely vulnerable.

The islands are also tied to a difficult chapter of history, as the British used them as a penal colony, the notorious Cellular Jail at Port Blair being its best-known remnant today.

What Is Lakshadweep?

Lakshadweep is a union territory made of 36 small islands and islets in the Arabian Sea, almost all of them coral atolls, with a combined land area of only around 32 square kilometres. The name means “a hundred thousand islands” in Sanskrit, though the real number is far smaller.

The territory includes about a dozen atolls, a few reefs and several submerged banks. Only around ten of the islands are inhabited, and the population is overwhelmingly Muslim and Malayalam-speaking, with Mahl spoken on Minicoy. The administrative capital is Kavaratti. The islands are grouped into the Amindivi, Laccadive and Minicoy sets, divided by the Nine Degree and Eleven Degree channels. Life centres on coconut, tuna fishing and, increasingly, controlled tourism.

The lagoons, clear water and bright reefs make Lakshadweep a world-class marine habitat, though the islands rise barely a few metres above sea level, which leaves them extremely sensitive to storms and rising seas.

How Are Coral Atolls Like Lakshadweep Formed?

Coral atolls like those of Lakshadweep form when coral reefs grow upward on top of a sinking volcanic or ridge foundation, leaving a ring of reef around a central lagoon. Charles Darwin first proposed this idea, and it remains the standard explanation.

Lakshadweep sits on the Chagos-Laccadive ridge, a long submarine ridge that runs south toward the Maldives and Chagos Archipelago. Over millions of years the original rock subsided, while reef-building corals kept growing toward the sunlit surface, building thick limestone caps. Waves then broke up the reef material and piled sand and coral rubble into low islands on the ring.

These atolls have no rivers and no soil to speak of, and fresh water exists only as a thin lens floating on salt water beneath the sand. That lens is easily damaged by over-pumping, storms or rising seas, which is why drinking-water security is a constant concern.

What Other Islands Does India Have?

India also has many near-shore, estuarine and river islands, including Majuli, Sagar Island, Pamban, Elephanta, the Gulf of Mannar islands, Sriharikota and the Sundarbans islands. These are quite different from the oceanic groups but matter greatly to the people and wildlife that depend on them.

Why Are India’s Islands Strategically Important?

India’s islands are strategically important because they add a very large exclusive economic zone to the country’s ocean territory and sit beside major shipping lanes, giving India a forward presence in the Indian Ocean. The Andaman and Nicobar group alone contributes a large proportion of India’s maritime zone.

Their position near the Strait of Malacca, through which a large share of world trade and energy shipments passes, makes them valuable for surveillance and defence. India has built up a joint military command in the Andamans and developed airstrips, ports and communications there. Lakshadweep lies astride sea lanes between West Asia and Southeast Asia and provides a base for fisheries and maritime patrol in the Arabian Sea.

The same strategic interest creates tension with conservation. Large infrastructure plans, such as the proposed port and township on Great Nicobar, promise economic and security gains, but critics warn about forest loss, impacts on the Shompen and the risk of building in a seismic zone.

What Threats Do India’s Islands Face?

The main threats to India’s islands are rising sea levels, coral bleaching, cyclones, tsunamis, erosion and development pressure. Low islands and reef-fringed coasts are among the first places where the effects of a warming climate become visible.

Sea-level rise threatens the low atolls of Lakshadweep and delta islands of the Sundarbans, some of which have already been lost to erosion and storm surge. Marine heatwaves cause mass coral bleaching in the Lakshadweep and Andaman reefs, which can lead to the collapse of the fish nurseries and natural breakwaters that the islands depend on. The December 2004 tsunami killed many people and changed the coastline across the Andaman and Nicobar Islands, especially the Nicobars. River islands like Majuli have lost a large share of their area to bank erosion over the last century.

Other pressures include overfishing, plastic and fuel pollution, invasive species, tourist crowding and demand for fresh water. Because islands are small and closed systems, damage tends to build up faster and be harder to undo than on the mainland.

How Are India’s Islands Being Protected?

India protects its islands through a mix of national parks, marine sanctuaries, biosphere reserves, coastal regulation rules and special tribal protection laws. These are meant to guard both the ecology and the people who depend on it.

Coastal Regulation Zone notifications limit building near the shore, while island-specific rules aim to guide tourism and construction in fragile areas. The Andaman and Nicobar group has numerous protected areas, including Mahatma Gandhi Marine National Park near Wandoor, and the Jarawa and Sentinelese are shielded by protected-tribe regulations. In Lakshadweep, marine sanctuaries and strict controls on certain activities protect lagoons and reefs. Scientific monitoring of coral health, seagrass beds and mangroves helps managers respond to bleaching and erosion.

The effectiveness of these measures depends on enforcement and on involving local communities, whose fishing, farming and traditional knowledge are essential to sustainable island management.

Bottom Line

The islands of India are far more than scenic dots on the map. The forested, quake-prone Andaman and Nicobar chain and the fragile coral atolls of Lakshadweep carry exceptional biodiversity, unique cultures and great strategic weight, while river and coastal islands show how closely land, water and people are linked. Their small size makes them fragile, so decisions about tourism, defence and infrastructure on them need unusual care.

Frequently Asked Questions

How many islands does India have?

India has well over a thousand islands and islets, with roughly 570 in the Andaman and Nicobar group and about 36 in Lakshadweep. The rest are coastal, estuarine and river islands, and the exact total depends on how small an island is allowed to be.

Which is India’s only active volcano?

Barren Island in the Andaman Sea is India’s only confirmed active volcano. It lies east of Port Blair, is uninhabited, and has erupted from time to time in recent decades.

What is the difference between the Andaman and Nicobar Islands and Lakshadweep?

The Andaman and Nicobar Islands are larger, hilly, forested and tectonic in origin, with a few volcanic peaks. Lakshadweep is made of low coral atolls on the Chagos-Laccadive ridge with almost no soil or surface freshwater.

Why can outsiders not visit North Sentinel Island?

The Sentinelese reject contact, and Indian law prohibits approaching the island to protect them from disease and violence. Authorities enforce an exclusion zone around it.

What is the largest river island in India?

Majuli, in the Brahmaputra in Assam, is usually cited as India’s largest river island and among the largest in the world. It has been shrinking because of flood and bank erosion.

Are India’s islands at risk from climate change?

Yes, low islands are especially vulnerable to sea-level rise, stronger cyclones and coral bleaching. The coral atolls of Lakshadweep and the delta islands of the Sundarbans are among the most exposed.

{“@context”:”https://schema.org”,”@graph”:[{“@type”:”FAQPage”,”mainEntity”:[{“@type”:”Question”,”name”:”How many islands does India have?”,”acceptedAnswer”:{“@type”:”Answer”,”text”:”India has well over a thousand islands and islets, with roughly 570 in the Andaman and Nicobar group and about 36 in Lakshadweep. The rest are coastal, estuarine and river islands, and the exact total depends on how small an island is allowed to be.”}},{“@type”:”Question”,”name”:”Which is India’s only active volcano?”,”acceptedAnswer”:{“@type”:”Answer”,”text”:”Barren Island in the Andaman Sea is India’s only confirmed active volcano. It lies east of Port Blair, is uninhabited, and has erupted from time to time in recent decades.”}},{“@type”:”Question”,”name”:”What is the difference between the Andaman and Nicobar Islands and Lakshadweep?”,”acceptedAnswer”:{“@type”:”Answer”,”text”:”The Andaman and Nicobar Islands are larger, hilly, forested and tectonic in origin, with a few volcanic peaks. Lakshadweep is made of low coral atolls on the Chagos-Laccadive ridge with almost no soil or surface freshwater.”}},{“@type”:”Question”,”name”:”Why can outsiders not visit North Sentinel Island?”,”acceptedAnswer”:{“@type”:”Answer”,”text”:”The Sentinelese reject contact, and Indian law prohibits approaching the island to protect them from disease and violence. Authorities enforce an exclusion zone around it.”}},{“@type”:”Question”,”name”:”What is the largest river island in India?”,”acceptedAnswer”:{“@type”:”Answer”,”text”:”Majuli, in the Brahmaputra in Assam, is usually cited as India’s largest river island and among the largest in the world. It has been shrinking because of flood and bank erosion.”}},{“@type”:”Question”,”name”:”Are India’s islands at risk from climate change?”,”acceptedAnswer”:{“@type”:”Answer”,”text”:”Yes, low islands are especially vulnerable to sea-level rise, stronger cyclones and coral bleaching. The coral atolls of Lakshadweep and the delta islands of the Sundarbans are among the most exposed.”}}]}]}