The railway journeys capable of crossing entire continents
This is the only atoll in the South Atlantic Ocean. A UNESCO World Heritage Site and wildlife haven, Rocas belongs to the Brazilian State of Rio Grande do Norte.
See also: Underwater paradise: the most beautiful coral reefs around the world.
Chuuk Lagoon, part of the larger Caroline Islands group, is a sheltered body of water in the central Pacific. The atoll consists of a huge protective reef that encloses a natural harbor. A main base for Japan during WWII, the seabed is dotted with wartime wrecks, in effect artificial reefs that attract a diverse array of marine life.
Did you know that the Maldives is the largest coral atoll in the world? A coral atoll is a ring-shaped coral reef or island that surrounds a lagoon, and this Indian Ocean archipelago boasts 26 of them. And did you also know that Huvadhu Atoll, anchored south of the Maldives, is the largest atoll in the world in terms of island numbers, with 255 lying scattered across an area of 1,216 sq mi (3,152 sq km)?
Atolls develop with underwater volcanoes, called seamounts. If a fringing reef forms around a volcanic island that erodes or subsides while the coral continues to grow upward, an atoll is created. The lagoon forms over the volcanic crater or caldera.
While the Maldives is arguably the best-known coral atoll (not least because of its status as one of the world's most exotic resort and diving destinations), there are literally thousands of these natural wonders dotted across the Indian and Pacific oceans. Eight atolls are found in the Caribbean Sea. The Atlantic Ocean, however, has no large group of atolls. Indeed, they are only found in the tropics and subtropics.
From the air, atolls resemble sapphires sprinkled on blankets of turquoise velvet. But the most rewarding way of exploring these extraordinary geological gems is by diving among the colorful and visually stunning reefs lying just below the water's surface. These fascinating marine ecosystems teem with tropical sea life, which thrive in some of the cleanest environments on the planet. Many atolls are designated UNESCO World Heritage Sites, recognized for their enchanting beauty and amazing biodiversity.
But these fragile marine reserves are under threat from global warming and the plastic waste epidemic.
The risk posed by rising sea levels is a credible one. If the issue of climate change is not addressed with the conviction it deserves, thousands of islands from the Maldives to Hawaii could become uninhabitable within decades. Similarly, the Great Pacific Garbage Patch is a collection of plastic and floating trash that research indicates is rapidly expanding.
But back to atolls and their beautiy—click through this gallery for an engaging journey to some of the most captivating atolls on the planet.
Part of the northwestern Hawaiian Islands, the atoll is named for the Pearl and the Hermes, a pair of English whaling ships that ran aground here in 1822. Around 20% of the world's population of black-footed albatrosses nest and breed here.
A coral atoll set in the Tuamotu archipelago in French Polynesia, Mataiva's distinctive oval-shaped lagoon is almost completely surrounded by land.
This Maldives atoll was off-limits to tourists as late as 1999. Today the main tourist islands of Loama Maamigili (pictured) and Meedhupparu feature several luxury resort-spa properties.
Onotoa is a low lying atoll situated in the Gilbert Islands in the Pacific Ocean. Onotoa means "six giants" in the Kiribati language, and the atoll is named so after a legend that tells of six sons who built a home out of huge coral boulders for their mother.
The archipelago is celebrated for its abundance of wildlife. Aves de Barlovento (the eastern group of cays) has a 5-mi (8-km) fringing reef.
Thulhaadhoo, one of the inhabited islands of the Baa Atoll, is highly regarded for its lacquerwork handicrafts made by locals.
One of three atolls of the Belize Barrier Reef (the other two being Glover's Reef and Lighthouse Reef), this is the largest coral atoll in Belize, and is a designated marine reserve and UNESCO World Heritage Site.
A coral atoll and the capital of the island nation of Tuvalu, Funafuti is littered with the remains of Japanese aircraft that crashed here during WWII. Tuvalu itself is a remote country of low lying atolls.
A coral atoll in the northern group of the Cook Islands in the south Pacific Ocean, Penrhyn sits atop the highest submarine volcano in the Cook Islands, rising 15,997 ft (4,876 m) from the ocean floor.
Part of a chain of atolls and coral islands that make up the Northern Line Islands set south of the Hawaiian Islands, the unoccupied Palmyra Atoll is supposed to be the location of the lost Inca treasure of the Esperanza, which struck a reef in 1816.
Aldabra is the world's second-largest coral atoll. Due to its remoteness and inaccessibility, the atoll has remained largely untouched by humans for the majority of its existence.
Comprised of four large coral islands that enclose a shallow lagoon—the largest lagoon in the Indian Ocean—this UNESCO World Heritage Site is home to over two-thirds of the world's population of giant tortoises.
Located 210 mi (340 km) northeast of Tahiti in the Tuamotu Islands, Tikehau Atoll is a popular French Polynesia tourist destination.
The southernmost atoll of the Maldives, Addu is the location of Addu City, one of the two cities of the archipelago. The white tern bird is found only on Addu in the Maldives, and is regarded as a symbol of the islands.
This central Pacific Ocean coral atoll is the first place on Earth to receive sunlight each day during much of the year. It became known as Millennium Island for its role in the millennium celebrations as one of the first points of land on the planet to usher in January 1, 2000 on the calendar.
Where to admire coral atolls, the sapphires of the sea
Spectacular in their beauty, they remain threatened by climate change
TRAVEL Geography
Did you know that the Maldives is the largest coral atoll in the world? A coral atoll is a ring-shaped coral reef or island that surrounds a lagoon, and this Indian Ocean archipelago boasts 26 of them. And did you also know that Huvadhu Atoll, anchored south of the Maldives, is the largest atoll in the world in terms of island numbers, with 255 lying scattered across an area of 1,216 sq mi (3,152 sq km)?
Atolls develop with underwater volcanoes, called seamounts. If a fringing reef forms around a volcanic island that erodes or subsides while the coral continues to grow upward, an atoll is created. The lagoon forms over the volcanic crater or caldera.
While the Maldives is arguably the best-known coral atoll (not least because of its status as one of the world's most exotic resort and diving destinations), there are literally thousands of these natural wonders dotted across the Indian and Pacific oceans. Eight atolls are found in the Caribbean Sea. The Atlantic Ocean, however, has no large group of atolls. Indeed, they are only found in the tropics and subtropics.
From the air, atolls resemble sapphires sprinkled on blankets of turquoise velvet. But the most rewarding way of exploring these extraordinary geological gems is by diving among the colorful and visually stunning reefs lying just below the water's surface. These fascinating marine ecosystems teem with tropical sea life, which thrive in some of the cleanest environments on the planet. Many atolls are designated UNESCO World Heritage Sites, recognized for their enchanting beauty and amazing biodiversity.
But these fragile marine reserves are under threat from global warming and the plastic waste epidemic.
The risk posed by rising sea levels is a credible one. If the issue of climate change is not addressed with the conviction it deserves, thousands of islands from the Maldives to Hawaii could become uninhabitable within decades. Similarly, the Great Pacific Garbage Patch is a collection of plastic and floating trash that research indicates is rapidly expanding.
But back to atolls and their beautiy—click through this gallery for an engaging journey to some of the most captivating atolls on the planet.