Mesa Verde, declarado Patrimonio de la Humanidad desde 1978. A great concentration of Anasazi Indian dwellings, built from the 6th to the 12th centuries, can be found on the Mesa Verde plateau in southwest Colorado, at an altitude of more than 2,600 metres. Some 3,800 sites have been recorded, including villages built on the plateau, and imposing cliffside sites, built of stone and comprising more than 200 houses. Yellowstone, declarado Patrimonio de la Humanidad desde 1978. Yellowstone was inscribed on the List of the World Heritage in Danger in 1995. In a vast natural forest in Wyoming, Yellowstone National Park covers more than 9,000 square kilometres. An impressive collection of geothermal phenomena can be observed there, including more than 3,000 geysers, fumaroles and hot springs. Established in 1872, Yellowstone is equally known for its wildlife, such as grizzly bears, wolves, bison and wapiti. Independence Hall, declarado Patrimonio de la Humanidad desde 1979. The Declaration of Independence and the Constitution were signed in this hall in the heart of Philadelphia, in 1776 and 1787 respectively. Since then, the universal principles set forth in these two documents of fundamental importance to American history have continued to guide lawmakers all over the world. Everglades National Park, declarado Patrimonio de la Humanidad desde 1979. Inscription on the List of World Heritage in Danger in 1993. This site at the southern tip of Florida has been called "a river of grass flowing imperceptibly from the hinterland into the sea". The exceptional variety of its water habitats has made it a sanctuary for a considerable number of birds and reptiles, as well as for threatened species such as the manatee. Grand Canyon National Park, declarado Patrimonio de la Humanidad desde 1979. Carved out by the Colorado River, the Grand Canyon, nearly 1,500 metres deep, is the most spectacular gorge in the world. Located in the state of Arizona, it cuts across the Grand Canyon National Park. Its horizontal strata retrace the geological history of the past 2 billion years. Prehistoric traces also remain of human adaptation to a particularly harsh environment. Redwood National Park, declarado Patrimonio de la Humanidad desde 1980.A region of coastal mountains bordering the Pacific Ocean north of San Francisco, Redwood National Park is covered with a magnificent forest of sequoia - redwood - trees, which are the tallest and most impressive in the world. The marine and land life are equally remarkable, in particular the sea lions, bald eagle and the endangered California brown pelican. Olympic National Park, declarado Patrimonio de la Humanidad desde 1981. Located in the northwest corner of Washington state, Olympic National Park is dominated by Mount Olympus (2,428 metres high), which gave the park its name. A great variety of landscapes and ecosystems can be found there, with a great wealth of marine life along its rocky coast, forests of giant conifers in the valleys where huge herds of wapiti roam, and craggy peaks overhanging some sixty active glaciers. Mammoth Cave National Park, declarado Patrimonio de la Humanidad desde 1981. Mammoth Cave National Park, located in the state of Kentucky, contains the largest network of natural caves and underground passageways in the world, characteristic examples of limestone formations. The park and its underground network shelter a varied flora and fauna, including a number of endangered species. Cahokia Mounds State Historic Site, declarado Patrimonio de la Humanidad desde 1982. About 15 kilometres north of St Louis (Missouri), Cahokia provides the most complete source of information on pre-Colombian civilizations in the regions of the Mississippi. It is a striking example of a pre-urban sedentary structure that allows for the study of a kind of social organisation about which no written traces exist. Great Smoky Mountains National Park, declarado Patrimonio de la Humanidad desde 1983. Stretching over more than 200,000 hectares, this exceptionally beautiful park is home to more than 3,500 plant species, almost as many trees (130 natural species) as in all of Europe. Many endangered animal species can also be found there, including what is probably the greatest variety of salamanders in the world. Relatively untouched, it gives an idea of temperate flora before the influence of humankind. La Fortaleza and San Juan Historic Site in Puerto Rico, declarado Patrimonio de la Humanidad desde 1983. A vital strategic point in the Caribbean Sea, the defensive structures built over four centuries (15th to 19th) to protect the city and the Bay of San Juan have left a rich display of European military architecture adapted to the harbours of the American continent. Yosemite National Park, declarado Patrimonio de la Humanidad desde 1984. Located in the heart of California, Yosemite National Park, with its "hanging" valleys, many waterfalls, cirque lakes, polished domes, moraines and U-shaped valleys, offers a view of all kinds of granite reliefs fashioned by glaciation. At 600 to 4,000 metres high, a great variety of flora and fauna can also be found here. The Statue of Liberty, declarado Patrimonio de la Humanidad desde 1984. Made in Paris by the French sculptor Bartholdi, with help on the metalwork from Gustave Eiffel, this symbolic monument to liberty was a gift from France on the centenary of American independence. Standing at the entrance of New York Harbor it has welcomed millions of immigrants to the United States of America since it was inaugurated in 1886. Hawaii Volcanoes National Park, declarado Patrimonio de la Humanidad desde 1987. Two of the most active volcanoes in the world, Mauna Loa (4,170 metres high) and Kilauea, tower over the Pacific Ocean at this site. Volcanic eruptions have created a continually-changing landscape, and the lava flows reveal surprising geological formations. Rare birds and endemic species can be found there, as well as forests of giant ferns. Monticello and University of Virginia in Charlottesville, declarado Patrimonio de la Humanidad desde 1987. Excellent examples of Neoclassicism, seen in the relationship of the buildings with nature and the blending of functionalism and symbolism, the mansion of Monticello and the University of Virginia reflect the design of their architect, Thomas Jefferson (1743-1826), who was strongly influenced by the Enlightenment. Chaco Culture National Historical Park, declarado Patrimonio de la Humanidad desde 1987. This national park, in north-west New Mexico, contains the most important remains of the Chaco culture, which was at its height between about 1020 and 1110. It was characterized by a very elaborate system of urban dwellings surrounded by villages and linked by a network of roads. Pueblo de Taos, declarado Patrimonio de la Humanidad desde 1992. Situated in the valley of a small tributary of the Rio Grande, this adobe settlement consists of dwellings and ceremonial buildings, representing the culture of the Pueblo Indians of Arizona and New Mexico. Waterton Glacier International Peace Park, declarado Patrimonio de la Humanidad desde 1995. In 1932 Waterton Lakes National Park (Alberta, Canada) was combined with the Glacier National Park (Montana, United States of America) to form the world’s first International Peace Park. Situated on the border between the two countries and offering outstanding scenery, the park is exceptionally rich in plant and mammal species as well as prairie, forest, and alpine and glacial features. Carlsbad Caverns National Park, declarado Patrimonio de la Humanidad desde 1995. In the state of New Mexico, this karstic network comprises 81 currently recognized caves. Among this high concentration of caves, outstanding because of their size and the profusion, diversity and beauty of mineral formations, the Lechuguilla cave stands out, forming an underground laboratory where geological processes can be studied in a virtually intact setting.
