From the iconic Golden Gate Bridge to the hills and hippies of Haight-Ashbury, San Francisco is one of America's most beautiful cities. The city by the bay attracts millions of visitors annually and lies at the cultural heart of California's Bay Area (which has a population of seven million). Famous for earthquakes (most of them minor), San Francisco is constantly on the move. Yosemite National Park lies at the heart of the magnificent Sierra Nevada mountain range in California and is an extraordinary natural wonder. It was named a UNESCO World Heritage Site in 1984. A glaciar-carved canyon, Yosemite offers some of the United States' most spectacular scenery with miles of granite cliffs, dazzling waterfalls, and some of the oldest trees in the world. The sparkling Merced River pours over Yosemite's cliffs through the valley and national park.