Yosemite Valley ( /joʊˈsɛmɨtiː/ yoh-SEM-i-tee) is a glacial valley in Yosemite National Park in the western Sierra Nevada mountains of California, carved out by the Merced River. The valley is about 8 miles (13 km) long and up to a mile deep, surrounded by high granite summits such as Half Dome and El Capitan, and densely forested with pines. A multitude of streams including Tenaya, Illilouette and Bridalveil Creeks join in the valley, and flow out of the valley's mouth as the Merced River, which eventually flows to the Pacific Ocean. The valley is renowned for its natural beauty, and is widely regarded as the centerpiece of Yosemite National Park, attracting visitors from around the world.