The Carriege Astronomical Observatory of Washington D.C. is located on the summit of Mount Wilson. In the Sierra Madre Mountains, 6,000 feet above sea level. The museum is open to the public. The view from Mount Wilson is an impressive sight, the beautiful San Gabriel Valley below, Pasadena, Los Angeles, and out in the Pacific, Santa Catalina Island is plainly visible. On a clear night, the lights of more than 60 cities are visible, a sight unequaled in all the world.