10 most visited national parks. In 2010, more than 281 million people visited America's 58 national parks, according to the National Park Service. To celebrate National Park Week, scroll through our slideshow highlighting the natural beauty preserved within the 10 most visited parks -- as well as the hidden gems that draw the fewest visitors.

Great Smoky Mountains National Park
No. 1 most visited: 9.46 million people | Formed: June 15, 1934
Location: State 1 | State 2 | Nearest city

An isolated valley and hiking are the main attractions at Great Smoky Mountains National Park, which spans two states. The park, which is part of an impressive mountain range, covers more than 520,000 acres
Grand Canyon National Park
No. 2 Most Visited: 4.39 million people | Formed: Feb. 26, 1919
Location: State | Nearest town

Most visitors observe Grand Canyon National Park from its South Rim entrance. At more than 1.2 million acres, the park's main attraction -- the Grand Canyon -- is one of the Seven Natural Wonders of the World.
Yosemite National Park
No. 3 most visited: 3.9 million people | Formed: Oct. 1, 1890
Location: State | Nearest town

Roughly the size of this mid-Atlantic state, Yosemite National Park covers more than 761,000 acres. The park is famous for its mountain range, giant Sequoia groves and lava waterfalls.
Yellowstone National Park
No. 4 most visited: 3.64 million people | Formed: March 1, 1872
Location: State 1 | State 2 | State 3 | Nearest town

Spanning three states, Yellowstone National Park is more than 2.2 million acres and has one of the highest-altitude lakes in North America. The oldest national park, it shelters a famous geyser and a native herd.
Rocky Mountain National Park
No. 5 most visited: 2.96 million people | Formed: Jan. 26, 1915
Location: State | Nearest city

Spanning more than 265,000 acres, Rocky Mountain National Park shelters some of the most impressive mountain views in the nation. The park also contains the Continental Divide.
Olympic National Park
No. 6 most visited: 2.84 million people | Formed: June 29, 1938
Location: State | Nearest city

With mountains, rain forests and coastlines, Olympic National Park contains more than 922,000 acres. The park shelters old-growth forests and region-specific herds.
Grand Teton National Park
No. 7 most visited: 2.669 million people | Formed: Feb. 26, 1919
Location: State | Nearest town

Named for the tallest peak in the mountain range, Grand Teton National Parkcovers more than 309,000 acres. A famous family donated its long-owned dude ranch for a park preserve.
Zion National Park
No. 8 most visited: 2.666 million people | Formed: Nov. 19, 1919
Location: State | Nearest town

Situated at the junction of a major plateau, watershed and desert, Zion National Park spans more than 146,000 acres. Among the park's natural wonders is Zion Canyon, including a major hiking destination: the Narrows.
Acadia National Park
No. 9 most visited: 2.5 million people | Formed: Feb. 26, 1919
Location: State | Nearest city

On the North Atlantic Coast, Acadia National Park spans more than 47,000 acres, which includes the sixth largest island in the continental U.S. A wealthy philanthropist demonstrated his fondness for the park by creating numerous carriage trails.
Cuyahoga Valley National Park
No. 10 most visited: 2.49 million people | Formed: Oct. 11, 2000
Location: State | Nearest city | Other city

Situated between two urban areas, Cuyahoga Valley National Park preserves nearly 33,000 acres. The park has an emphasis on rural living along an important river that became infamous for an environmental disaster.