Environment Planet Earth The 7 Natural Wonders of the World By Maria Emerick Maria Emerick Maria Emerick is a former writer for Treehugger. She holds a degree in environmental science from Marywood University. Learn about our editorial process Updated May 28, 2021 Mount Everest is shared by Nepal and China. Emad aljumah / Getty Images Share Twitter Pinterest Email Environment Weather Outdoors Conservation The practice of compiling "wonders" into groups of seven dates back to Ancient Greece, when Philo of Byzantium wrote a book in 225 B.C. entitled "On the Seven Wonders." Now referred to as the Seven Ancient Wonders of the World, these included the Great Pyramid of Giza and the Colossus of Rhodes. People have created lists of wonders since, showcasing everything from feats of human engineering to magnificent natural landscapes. The most commonly accepted list of the Seven Natural Wonder came from an article published by CNN, the broadcasting network, in 1997. The conservation organization Seven Natural Wonders protects these. To be considered a natural wonder, a site must not be naturally occurring, created without human intervention. Learn about the Seven Natural Wonders of the World here. 1 of 7 Grand Canyon Dean Fikar / Getty Images The Grand Canyon canyon in the United States is called "grand" for a reason—at more than a mile deep, 277 river miles long, and between four and 18 miles wide, it is one of the largest and longest canyons in the world. It covers an area of over 9.5 million square miles. This natural wonder was formed through erosion by the Colorado River, its distinct layers featuring rock scientists estimate to be between 30 and 70 million years old. Visitors can see the Grand Canyon in person by going to Grand Canyon National Park in Arizona and viewing it from a lookout, or get up close and personal by white water rafting in the river or hiking through the canyon. 2 of 7 Great Barrier Reef Daniel Osterkamp / Getty Images Covering roughly 216,000 square miles of the Coral Sea, the Great Barrier Reef is the largest coral reef system in the world. More than 2,500 individual reefs and 900 islands make up this natural wonder, which stretches over 1,200 miles along the coastline of northeastern Australia. This reef is incredibly biodiverse. More than 1,500 species of fish, 4,000 species of mollusk, and 400 species of coral can be found in the reef's extensive ecosystems. Naturally occurring stressors such as global warming and disturbance by humans put the Great Barrier Reef at risk, but this, like many of the seven wonders, is a UNESCO World Heritage Site and the focus of many conservation efforts. 3 of 7 Harbor of Rio de Janeiro Reed Kaestner / Getty Images The harbor that wraps around Rio de Janeiro, Brazil, is the largest natural bay in the world and a sight to behold. Erosion by the Atlantic Ocean carved out this natural wonder, which is also known as Guanabara Bay. The land around the harbor is dotted with mountains, among them the Hills of Tijuca at 3,350 tall, Corcovado Peak at 2,310 feet tall, and Sugar Loaf at 1,296 feet tall. Large cargo ships and recreational yachts can often be seen in Rio de Janeiro's harbor. This is a popular tourist destination and a critical waterway for shipping. 4 of 7 Mount Everest zhengjie wu / Getty Images Mount Everest on the border of Nepal and Tibet is the tallest mountain in the world. Its peak is the highest point above sea level on Earth with an altitude of almost 29,032 feet. This mountain is still growing as shifting tectonic plates continue pushing it upward, the same way it first began forming millions of years ago. Brave visitors can hike Mount Everest, but not without plenty of experience and the accompaniment of trained guides. Such high altitudes deprive the body of oxygen, making an already difficult trek even more physically taxing, and expeditions take months to complete. Climbing Mount Everest is dangerous and only for highly skilled climbers. 5 of 7 The Northern Lights Thomas Niedermueller / Getty Images The Northern Lights generally appear in the Arctic around Iceland, Greenland, Canada, and the northernmost portions of Scandinavia. They can be seen as wave- or sheet-like lights in the sky (conditions), often greenish or reddish in color and magnificently bright, at altitudes as great as 620 miles. Auroras are caused by the emission of photons or particles of light by electrons in the atmosphere. These lights, called aurora borealis, are largely unpredictable, but scientists count on their appearance for researching interactions between magnetism and optics. The best time to see these dancing lights is between the months of March and April or between September and October. 6 of 7 Paricutin Volcano Torresigner / Getty Images The Paricutin Volcano is a cinder cone volcano located in Michoacán, Mexico. The world has watched this volcano grow since it began forming in 1943 in farmer Dionisio Pulido's cornfield, and it is actually the youngest volcano in the world. According to Pulido, it grew between two and 2.5 meters in height within the first 24 hours of its formation. As of 2021, it is estimated to be between 9,101 and 10,397 feet tall. Paricutin erupted from 1943 to 1952. Visitors can view this natural wonder from its base or even from its crater. 7 of 7 Victoria Falls Ignacio Palacios / Getty Images Victoria Falls, the largest waterfall in the world, is located in southern Africa on the borders of Zambia and Zimbabwe. The Zambezi River serves as the falls' water source. Victoria Falls measures over 5,600 feet across and 3,000 feet high, and it has an average depth of about 328 feet. This sprawling natural wonder occupies portions of the Victoria Falls National Park of Zimbabwe, the Zambezi National Park of Zimbabwe, and the Mosi-oa-Tunya National Park of Zambia. Rainbows can often be seen arching over these falls, even at night when the water refracts the light of the moon (these are referred to as "moonbows"). If you do visit, be prepared to get wet—the Victoria Falls spray plume has been known to reach a height of 1,640 feet. View Article Sources "Grand Canyon National Park." Grand Canyon. National Park Service. "7 Natural Wonders of North America." Seven Natural Wonders. "Geology." Grand Canyon. National Park Service. "Great Barrier Reef." United Nations Educational, Scientific and Cultural Organization. "Harbor of Rio de Janeiro." Seven Wonders. Wilkinson, Freddie. "Mount Everest Is More Than Two Feet Taller, China and Nepal Announce." National Geographic. 9 Feb. 2021. "What Are the Northern Lights?" Library of Congress. "Understanding Basaltic Volcanic Processes by Remotely Measuring the Links Between Vegetation Health and Extent, and Volcanic Gas and Thermal Emissions Using HyspIRI-Like VSWIR and TIR Data." NASA HyspIRI Science and Application Workshop, 2015. "Paricutin Volcano." Seven Natural Wonders. "Mosi-oa-Tunya / Victoria Falls." United Nations Educational, Scientific and Cultural Organization.