Singapore to Hong Kong

Coral can grow in many different forms, taking millions of years to create a full atoll-sized reef.

The red dots on this map mark the locations of coral reefs in the world's oceans. There is a high concentration of reefs in the South China Sea, which makes up most of the sea's islands.

The Spratly Islands are the largest collection of islands in the South China Sea, with more than 600 cays, atolls, rocks and sandbanks making up the archipelago.

The Paracel Islands are divided into two groups: the Amphitrite Group to the east and the Crescent Group to the west. In total there are around 30 islands in the archipelago.

Coral is created by polyps like these, which are closely related to sea anemones. Hard coral is made of calcium carbonate secreted by the polyps, and protects them from predators and strong currents.

It is thought that atolls are formed when coral reefs grow around the flanks of volcanoes at sea. As the volcano dies and shrinks, the coral continues to grow resulting in a circular reef around a shallow lagoon.

The Pratas Islands are the smallest of the three South China Sea archipelagos, comprised of only three islands.

The South China Sea is peppered with tiny islands, divided into three archipelagoes. The Spratly Islands (shown to the south) is the largest with more than 600 islands and islets.

Satellite image showing the Cresent Group of the Paracel Islands. The familiar atoll shapes can be seen here.

A satellite image of a cay which makes up part of the Spratly Islands, more than 1,000km south of Hainan Island in the South China Sea.

An aerial view of the Crescent Group of Paracel Islands: Drummond Island is the largest, with Money Island at the top of the group and Observation Group to the right.

Discovery Reef, part of the Paracel Islands, as seen from a satellite. Discovery Reef is one of the larger reef groups to the south west of the islands.

One of the reefs that form the Spratly Islands off the coast of the Philippines.

A map of the South China Sea, showing the disputed Paracel and Spratly Islands, and highlighting the known oil and gas reserves across the region.

1947 - Chinese map showing Chinese territory in the South China Sea, encompassing the Paracel and Spratly Islands.

Airplane landing strip on Swallow Reef in the Spratly Islands.

A letter sent by the North Vietnamese prime minister to the Chinese Premier in 1958 supporting China's claim to the islands. South Vietnam disputed this; 16 years later the Battle of the Paracels occurred.

Vietnamese guards keep watch at Amboyna Cay in the Spratly Islands.

This diagram illustrates national claims over the South China Sea Islands. China and Vietnam claim the largest stakes, while Malaysia, Brunei and the Philippines claim ownership too.

Map of the Spratly Islands showing occupied islands with flags representing the occupying nation, as of 2008.

Swallow's Reef in the Spratly Islands currently claimed by Malaysia. The Malaysian Navy has held an offshore post here since 1983, and have constructed an airstrip.

A Dutch map from 1754 depicting the coast of China and Vietnam with Hainan and the Paracel and Spratly Islands.

Vietnamese troops parading on Changsha (Spratly Islands). Sovereignty over the islands is claimed by China, Vietnam and the Philippines.

A Chinese map of the Paracel Islands. Vietnam strongly contests Chinese claim over the islands, with both nations believing that they belong to them. Both countries controlled parts of the islands before 1974.

A tanker off the coast of Hainan prepares to sail across the South China Sea. More than 250 cargo ships and containers pass through the Spratly Islands area every day.

A Vietnamese propaganda poster declaring ownership of the Paracel and Spratly Islands. Ownership of the islands is disputed by a number of countries, including China and Vietnam.

Green and Hawksbill Turtles are often found nesting on the Spratly Islands, especially those which remain uninhabited by humans.

Increased human activity in the South China Sea has led to a decline in wildlife populations - Amboyna Cay in the Spratly Islands has been particularly built up in recent years, affecting local wildlife.

The South China Sea Islands are home to large seabirds such as this brown booby. In recent years, numbers of birds on the islands has begun to decline due to increased human activity in the area.

Large numbers of seabirds, such as this crested tern, can be found on the Paracel and Spratly Islands where they come to nest and overwinter.

White terns can be found in the South China Sea Islands, where they come to nest each year.

Vuladdore Reef is one of the smaller islands of the Paracels, unoccupied by humans.

A female Green turtle prepares to return to the South China Sea after laying her eggs on land.

Hawksbills and other species of turtles use the sandy shores of the South China Sea to lay their eggs.

Numbers of Hawksbill turtles have been in decline in the South China Sea. They are caught and sold as desirable delicacies in China.

The critically endangered Hawksbill turtle finds its habitat in the shallow warm waters of the South China Sea Islands.

Green turtles can be found in the waters surrounding the South China Sea Islands. They use the sandy islands to lay their eggs.

An untouched atoll in the South China Sea archipelago of the Spratly Islands. The coral reefs that form these atolls provide homes for an abundance of marine life.

A red-footed booby chick. These birds are often found on the Spratly Islands, where they spend time nesting and wintering on the smaller and less disturbed islands.