Grand Canyon located in the United States in the state of Arizona is considered to be one of the seven natural wonders of the world. Having a history of billion years of the Earth's geological history, geologists believe that is was formed by the deep carving of the River Colorado. More details on the history & formation of this canyon can be found in the Wikipedia
Yosemite National Park located in the central eastern part of the California state of the United States of America is a beautiful U shaped valley. Its declared as a UNESCO World Heritage Site & it attracts a lot of tourists every year. Its around 4 hrs drive from San Francisco.
Tunnel View, Yosemite National Park
Upper Yosemite Falls