Yosemite National Park is in the mountains of the Sierra Nevada, eastern California, in the United States. With a total area of 3079 km2, it is the third largest park in California. Declared a national park in 1890, Yosemite is the second oldest in US history, after that of Yellowstone. Over 3.5 million visitors attend every year, making it, with the Colorado Grand Canyon and the Great Smoky Mountains, one of the most visited natural sites in the country. Its waterfalls and spectacular granite domes attract each year thousands of hikers and climbers from around the world. Yosemite is a mountain park whose natural and landscape diversity has been recognized world heritage by UNESCO in 1984. But the intense tourist activity in spring and summer, poses environmental problems in the valley Yosemite.
