Environment Planet Earth The 7 Natural Wonders of the World By Maria Emerick is a registered dietician with a passion for the healing power of food and a background in environmental science. our editorial process Maria Boland Updated May 18, 2020 Aerial view of Mount Everest. Emad aljumah / Getty Images Share Twitter Pinterest Email Environment Weather Outdoors Conservation Seven Natural Wonders is a project created with the mission of protecting and promoting the original seven natural wonders of the world. The list that is commonly accepted as the "Natural Wonders" was compiled by CNN; at the time, there was a debate as to how large the list should be, and no official consensus was reached. A natural wonder must be a clearly defined natural site or natural monument that was not created or significantly altered by humans. Each of the original seven natural wonders is in existence today and they all provide visitors with amazement and wonder. 1 of 7 Grand Canyon (North America) Dean Fikar / Getty Images The canyon is 277 river miles long. The width ranges from 4 to 18 miles. The depth is over one mile. Majority is located within Grand Canyon National Park. Created by erosion of Colorado River. NOT the steepest or the longest canyon in the world. Recognized as a natural wonder because of the overall scale and size combined with the beautifully colored landscape. Offers a variety of lookouts. Provides visitors with a view that cannot be matched. Ways of exploring the canyon on foot Day/night hikes Overnight backpacking trips On back of a mule White water rafting Observatory ramp Hiking the trails near edges A number of lava flows are Cenozoic in age, and some of them spill into the canyon. The walls of the canyon are mostly cut into horizontal rock layers of Paleozoic age. There is an angular unconformity at the bottom of the Paleozoic layers. An angular unconformity is the result of tilting and eroding of the lower layers before the upper ones are deposited. These tilted and eroded layers are Precambrian in age. 2 of 7 Great Barrier Reef (Oceania) Daniel Osterkamp / Getty Images Quick facts: It is the largest coral reef system in the world. Consists of over 2,900 separate reefs. Stretches over 1,600 miles. Can be seen from outer space. The 133,000 square miles includes 900 islands. Located in the Coral Sea, off the coast of Queensland in northeast Australia. Reef structure composed of and built by billions of tiny organisms, known as coral polyps. Threats to the reef: A large part of the reef is protected by the Great Barrier Reef Marine Park, which helps to limit the impact of human use, such as overfishing and tourism. Other environmental pressures to the reef and its ecosystem include water quality from runoff, climate change accompanied by mass coral bleaching, and cyclic outbreaks of the crown-of-thorns starfish (which eat coral polyps). Mass coral bleaching events due to rising ocean temperatures occurred in the summers of 1998, 2002 and 2006, and coral bleaching will likely become an annual occurrence. Biodiversity in the reef: Supports many vulnerable or endangered species, some of which may be endemic to the reef system. Includes: 30 species of whales, dolphins and porpoises; 6 species of sea turtles; 15 species of seagrass; around 125 species of shark, stingray, skates; close to 5,000 species of mollusck; 9 species of seahorse; 7 species of frogs; 17 species of sea snake; more than 1,500 species of fish; 400 species of corals (hard/soft). (And that's just aquatic organisms.) Marine algae or seaweed create mini-ecosystems on their surface which have been compared to a rain forest cover. 3 of 7 Harbor of Rio de Janeiro (South America) Reed Kaestner / Getty Images Quick facts: Located around Rio de Janeiro, Brazil. Surrounded by protruding mountains that include Sugar Loaf at 1,296 feet, Corcovado Peak at 2,310 feet, and the Hills of Tijuca at 3,350 feet. Rio de Janeiro translates "River of January" in Portuguese. Created by erosion from the Atlantic Ocean. Harbor offers many different perspectives to visitors/tourists at various heights. The locals are so proud of their geologically defined home that they say, "God made the world in six days and on the seventh he concentrated on Rio." It used to be a tropical rainforest full of flourishing life, but is now used by supertankers and yachts as a harbor. The bay's vastness has been shrinking. With usable land at a premium, landmass has twice been altered. In the 1920s and again in the 1960s, small hills had pipes placed through and on them to create more livable land. The "updated" land now houses an airport, a six-lane highway, parkland and beaches, the city's modern art museum, and other 20th-century landmarks as Rio looks to its great bay for elbow room. 4 of 7 Mount Everest (Asia) zhengjie wu / Getty Images Quick facts: Highest mountain in the world, represents the highest spot on Earth's surface. Summit reaches a peak of 29,029 feet. Located in the Himalaya mountains on the border between Nepal and Tibet, China. Also known as Chomolungma. Shifting tectonic plates continue to push Everest upward, along with the whole Himalaya mountain range, at 1.6 to 3.9 inches per year. The best way to experience Mount Everest is by making the hike to the base of the mountain. For more experienced individuals, a climb to the upper base camp. But this experience is costly; the Nepal government now requires potential climbers to purchase a $25,000USD climbing permit. The best season to explore it is fall, during the months of October and November which are the start of the dry season (and of course when it's not snowing). Prior experience carrying a heavy pack for multiple days serves as excellent preparation for this climb. Climbers must be able to carry an average of 30 lbs or more and be physically and mentally prepared to deal with strenuous situations at high altitudes. Climbers need to be in excellent physical condition for both personal enjoyment and to be important team members. 5 of 7 Aurora (The Arctic and Antarctica) FEBRUARY / Getty Images Quick facts: Also known as polar auroras The northern lights (aurora borealis) are the most notable, but a southern aurora (aurora australis) does occur in the southern hemisphere No specific or consistent measurements (design, size, pattern, color) Appear as glowing sheets or dancing waves The chances of experiencing the northern lights will increase as one approaches the magnetic pole. The magnetic pole can be found in the Arctic islands of Canada. Unfortunately, it cannot predict when the lights will appear, but the best chances of witnessing the northern lights occur between the months of March to April and September to October (equinoxes). Named after the Roman goddess of dawn, Aurora, and the Greek name for north wind, boreas. Auroras seen near the magnetic pole may be high overhead, but from further away, they illuminate the northern horizon as a greenish glow or sometimes a faint red, as if the sun were rising from an unusual direction. Why so many colors? Auroras are the result of the emissions of photons in the Earth's upper atmosphere (50 miles), from ionized nitrogen atoms regaining an electron, and oxygen and nitrogen atoms returning from an excited state to ground state. They are ionized or excited by the collision of solar wind particles being funneled down, and accelerated along, the Earth's magnetic field lines. Oxygen emissions are green or brownish-red, depending on the amount of energy absorbed. Nitrogen emissions are blue or red; blue if the atom regains an electron after it has been ionized, red if returning to ground state from an excited state. 6 of 7 Parícutin Volcano (North America) Jurhi Valencia Heredia / Getty Images Quick facts: It is a cinder cone volcano. Located in Mexican state of Michoacán. Official height varies from 9,101 to 10,397 feet. Last erupted in 1952. Known as youngest volcano in America. Established as natural wonder because mankind witnessed its birth. Volcano was also fast growing, reaching 3/4 of its size within the first year. Volcanism is a common part of the Mexican landscape. Parícutin is the youngest of more than 1,400 volcanic vents that exist in the Trans-Mexican Volcanic Belt and North America. The volcano is unique in the fact that its formation was witnessed from its very beginning. Three people died as a result of lightning strikes caused by eruptions, but no deaths were attributed to the lava or asphyxiation. 7 of 7 Victoria Falls (Africa) Ignacio Palacios / Getty Images Quick facts: It is also called Mosi-oa-Tunya meaning "mist that thunders." It is the largest waterfall based on width and height. It is one mile wide and 360 feet high. Two national parks (Zambia) and (Zimbabwe) protect the falls. Victoria Falls is located in southern Africa on the borders of Zambia and Zimbabwe. The Zambezi River serves as the falls' water source. There are two seasons to the Victoria Falls area. The rainy season runs from late November to early April and the remaining months account for the dry season. One would imagine that the rainy season with more water would make the falls more spectacular, but the additional water makes it impossible to see the base of the falls. The rainbow can be seen during any part of the day, but it seems to be brightest during the early part of the day. At full moon, a "moonbow" can be seen in the spray instead of the usual daylight rainbow. The spray from the falls rises over 1,300 feet, sometimes even twice as high, and is visible from 30 miles away. Victoria Falls is roughly three times the height of Niagara Falls and well over twice the width of its Horseshoe Falls. In height and width, Victoria Falls competes only with South America's Iguazu Falls.