Grand Canyon in the context of "Colorado River"

In geology, a rock (or stone) is any naturally occurring solid mass or aggregate of minerals or mineraloid matter. It is categorized by the minerals included, its chemical composition, and the way in which it is formed. Rocks form the Earth's outer solid layer, the crust, and most of its interior, except for the liquid outer core and pockets of magma in the asthenosphere. The study of rocks involves multiple subdisciplines of geology, including petrology and mineralogy. It may be limited to rocks found on Earth, or it may include planetary geology that studies the rocks of other celestial objects.

Rocks are usually grouped into three main groups: igneous rocks, sedimentary rocks and metamorphic rocks. Igneous rocks are formed when magma cools in the Earth's crust, or lava cools on the ground surface or the seabed. Sedimentary rocks are formed by diagenesis and lithification of sediments, which in turn are formed by the weathering, transport, and deposition of existing rocks. Metamorphic rocks are formed when existing rocks are subjected to such high pressures and temperatures that they are transformed without significant melting.

The Apurímac River (Quechua: Apurimaq mayu IPA: [ˈapʊ ˈɾɪmaχ ˈmajʊ]; Spanish: río Apurímac, IPA: [ˈri.o apuˈɾimak]; from Quechua apu 'chief' and rimaq 'the one who speaks, oracle', thus 'the chief oracle') rises from glacial meltwater of the ridge of the Mismi, a 5,597-metre-high (18,363 ft) mountain in the Arequipa Province in the south-western mountain ranges of Peru, 10 km (6.2 mi) from the village Caylloma, and less than 160 km (99 mi) from the Pacific coast. It flows generally northwest past Cusco in narrow gorges with depths of up to 3,000 m (9,800 ft), almost twice as deep as the Grand Canyon, its course interrupted by falls and rapids. Of the six attempts to travel the full length of the Apurímac so far, only two have been successful.

After 730 kilometres (450 mi), the Apurímac joins the Mantaro River and becomes the Ene River, 440 m (1,440 ft) above sea level; then after joining the Perené River at 330 m (1,080 ft) above sea level, it becomes the Tambo River; when it joins the Urubamba at 280 m (920 ft) above sea level the river becomes the Ucayali, which is the main headstream of the Amazon. Sometimes the complete river from its source to its junction with the Ucayali, including the rivers Ene and Tambo, is called "Apurímac", with a total length of 1,070 km (660 mi).

Chihuahua, officially the Free and Sovereign State of Chihuahua, is one of the 31 states which, along with Mexico City, are the 32 federal entities of Mexico. It is located in the northwestern part of Mexico and is bordered by the states of Sonora to the west, Sinaloa to the southwest, Durango to the south, and Coahuila to the east. To the north and northeast, it shares an extensive border with the U.S. adjacent to the U.S. states of New Mexico and Texas. The state was named after its capital city, Chihuahua City; the largest city is Ciudad Juárez. In 1864 the city of Chihuahua was declared capital of Mexico by Benito Juárez during the Reform War and French intervention until 1867. The city of Parral was the largest producer of silver in the world in 1640. During the Mexican War of Independence, Miguel Hidalgo was executed on July 30, 1811, in Chihuahua city.

Although Chihuahua is primarily identified with its namesake, the Chihuahuan Desert, it has more forests than any other state in Mexico, aside from Durango. Due to its varied climate, the state has a large variety of fauna and flora. The state is mostly characterized by rugged mountainous terrain and wide river valleys. The Sierra Madre Occidental mountain range, part of the continental spine that also includes the Rocky Mountains, dominates the state's terrain, and is home to the state's greatest attraction, Las Barrancas del Cobre, or Copper Canyon, a canyon system larger and deeper than the Grand Canyon. The state also has the largest crystal cave in Mexico known as the Naica cave discovered in 2001. Chihuahua is also home to the archaeological site of Paquimé in Casas Grandes that was created by the people of the Mogollon culture of Northern Mexico and is recognized as an UNESCO World Heritage site. Chihuahua is the largest state in Mexico by area, with an area of 247,455 square kilometres (95,543 sq mi), it is slightly larger than the United Kingdom, and slightly smaller than Wyoming, the tenth largest US state by area. The state is consequently known under the nickname El Estado Grande ('The Great State' or 'The Big State').

In the United States, tourism is a large industry that serves millions of international and domestic tourists yearly. Foreigners visit the U.S. to see natural wonders, cities, historic landmarks, and entertainment venues. Americans seek similar attractions, as well as recreation and vacation areas.

Tourism in the United States grew rapidly in the form of urban tourism during the late nineteenth and early twentieth centuries. By the 1850s, tourism in the United States was well established both as a cultural activity and as an industry. New York City, Los Angeles, Chicago, Boston, Philadelphia, Washington, D.C., and San Francisco, all major U.S. cities, have attracted numerous tourists since the 1890s. By 1915, city touring had marked significant shifts in the way Americans perceived, organized, and moved.

A canyon (from Spanish cañón; archaic British English spelling: cañon), gorge or chasm, is a deep cleft between escarpments or cliffs resulting from weathering and the erosive activity of a river over geologic time scales. Rivers have a natural tendency to cut through underlying surfaces, eventually wearing away rock layers as sediments are removed downstream. A river bed will gradually reach a baseline elevation, which is the same elevation as the body of water into which the river drains. The processes of weathering and erosion will form canyons when the river's headwaters and estuary are at significantly different elevations, particularly through regions where softer rock layers are intermingled with harder layers more resistant to weathering.

A canyon may also refer to a rift between two mountain peaks, such as those in ranges including the Rocky Mountains, the Alps, the Himalayas or the Andes. Usually, a river or stream carves out such splits between mountains. Examples of mountain-type canyons are Provo Canyon in Utah or Yosemite Valley in California's Sierra Nevada. Canyons within mountains, or gorges that have an opening on only one side, are called box canyons. Slot canyons are very narrow canyons that often have smooth walls.

43°00′34″N 46°49′40″E / 43.00944°N 46.82778°E / 43.00944; 46.82778

The Sulak Canyon (Avar: Сулахъ кӏкIал, Russian: Сулакский каньон) is a steep-sided deepest canyon in Europe carved by the Sulak River in Dagestan, Russia. The Sulak Canyon is 53 kilometres (33 mi) long, and attains a depth of over a mile (1,920 meters or 6,300 feet). It is 63 meters deeper than the Grand Canyon in the US and 620 meters deeper than the Tara River Canyon in Balkans.