On Tanna Island in Vanuatu, you can get up close and personal with an active volcano. Mount Yasur is famous for having easy access to its rim, where visitors can take a short 10-minute hike that safely passes through steaming ash fields and view bursts of lava. The nation of Vanuatu is a chain of 13 principal islands and many smaller islets, located about 1,000 miles east of Australia.

Most of Lake Eyre is typically dry, but on the rare occasions when the lake does fill up, it is the largest lake in Australia — covering more than 3,600 square miles. That’s nearly double the size of the next largest lake in Australia, Lake Torrens. Eyre also sits at the lowest natural point on the continent, 49 feet below sea level.

New Zealand is no stranger to stunning natural formations, and Blue Lake in Nelson Lakes National Park on the South Island is just one such example. In 2009, it officially became the clearest freshwater lake ever reported when a team of researchers from the National Institute of Water and the Atmosphere (NIWA) began running optical tests and found nearly pure clarity, which is extremely rare.

The South Pacific island nation of Samoa is sometimes referred to as the “Cradle of Polynesia” — the original homeland of all Polynesian peoples. The island gained independence from New Zealand in 1962. About one-fifth of the population of 200,000 lives in the nation's only town and capital, Apia.

The Tasman Sea spans 900,000 square miles and separates the island nations of Australia and New Zealand in the southwest Pacific. The sea lies just south of the Coral Sea and connects with the Bass Strait, which separates Australia from Tasmania and leads to the Indian Ocean. Both Australians and Kiwis colloquially refer to the sea as “the ditch,” just as Brits and Americans refer to the Atlantic as “the pond.”

Puncak Jaya, also called Carstensz Pyramid, is the world’s highest island peak, rising 16,024 feet above the western half of the island of New Guinea, in the Indonesian province of Papua. Puncak Jaya is considered one of the Seven Summits — the tallest mountain on each continent — because it is the tallest in Oceania.

Named for nearly 600 species of reef-building corals, the Coral Triangle is a diverse marine habitat in the western Pacific Ocean. It covers around 2.2 million square miles of ocean, from the Philippines in the north to the Solomon Islands at its southeastern point. Here, you can see six of the world’s seven marine turtle species, along with more than 2,000 species of fish.

The easternmost point of the United States is Point Udall in the U.S. Virgin Islands, while the westernmost point is Point Udall in Guam. Originally named Orote Point for its position on Guam's Orote Peninsula, the easternmost site was renamed in 1987 in honor of Morris Udall, the former congressman from Arizona. Point Udall in the Virgin Islands is named after his brother, Stewart, who served as secretary of the Interior under two Presidents.

Newly discovered Zealandia could have been Earth’s eighth continent, but there’s one problem — 94% of it is underwater. New Zealand’s North and South islands make up most of the above-sea-level landmass, and New Caledonia is its second-largest entity. Located just north of New Zealand, New Caledonia is a French territory made up of dozens of islands.

Samoa is central to Polynesia, influencing the region’s culture — especially music, dance, and visual art — for centuries. Savai‘i Island, Samoa’s largest island, is said to be Hawaiki, the mythological Polynesian homeland. Samoa consists of nine islands, but only four (Upolu, Savai‘i, Manono, and Apolima) are inhabited.

Located just north of Australia, New Guinea is the world’s second-largest island. The territory is split almost equally in half: The western side belongs to Indonesia, and the eastern half is the independent country Papua New Guinea. Most of the island is mountainous and covered in rainforests. The island is rich in both plant life and wildlife, particularly reptiles, marsupials, and birds, both flightless and tropical.

The Mariana Trench is a crescent-shaped depression that descends roughly 36,000 feet deep, making it the deepest trench on Earth. To put its depth into perspective, if Mount Everest were placed inside the trench, its peak would still be a mile underwater. At Challenger Deep, the trench’s deepest point, remotely operated underwater vehicles explore the alien-like world devoid of natural light.

Also called “low islands,” coral islands barely reach above sea level and are made by coral reefs that build up around volcanic islands. Many form a coral atoll — as the volcanic island erodes, all that's left is a ring-shaped coral reef with a lagoon at its center. Micronesia and Polynesia, two subregions of Oceania, are full of atolls, which are typically uninhabited.

The largest country in Oceania is Australia. On the opposite end of the spectrum, Nauru claims the title of smallest country, covering just 8.1 square miles. The island nation is located just 25 miles south of the equator in Micronesia and is home to fewer than 15,000 people.

More than 40 countries across the world don’t have borders on an ocean or sea. You won’t find any of them in North America or Oceania, the only two populated continents absent of landlocked nations. Antarctica, of course, has no landlocked countries, simply because it has no countries — although seven countries do lay claim to parts of the continent.

There are 14 countries in the region of Oceania, which encompasses a wide swath of the South Pacific. These countries include Australia, New Zealand, Fiji, Kiribati, the Marshall Islands, Micronesia, Nauru, Palau, Samoa, Tuvalu, the Solomon Islands, Vanuatu, Papua New Guinea, and Tonga. Other islands — such as the Cook Islands, French Polynesia, New Caledonia, Guam, and American Samoa — are also part of the region but are territories of other countries.

The Great Barrier Reef covers roughly 135,000 square miles of ocean off the coast of Queensland, Australia. The natural wonder is home to 400 types of coral, 1,500 species of fish, and many other threatened or endangered animals, such as the dugong and green sea turtle, which is why scientists are working to protect this crucial habitat.

Tasmania is a large island located about 150 miles off the coast of southern Australia. One of Australia’s six states, Tasmania is surrounded by a number of smaller islands. It was originally called Van Diemen's Land, but the island was renamed after Dutch explorer Abel Janszoon Tasman, the first European to encounter the island.

The Ring of Fire is a horseshoe-shaped belt around the rim of the Pacific Ocean where many earthquakes and volcanic eruptions occur. Many of Oceania’s islands, especially in Melanesia (a subregion), were formed because of it. Known as volcanic islands, they are characterized by their steep peaks and ridges that stretch to the coastline.

Oceania is a region in the South Pacific Ocean that includes the islands of Australia, Zealandia, Melanesia, Micronesia, and Polynesia. Defining what Oceania is can be tricky. Sometimes, it’s considered the seventh continent, but technically, it’s a region that includes the seventh and smallest continent, Australia. To avoid confusion, Australia and Oceania are typically lumped together when listing the continents.