Golden Gate Bridge
The orange towers of the Golden Gate Bridge-probably the most beautiful,certainly the most photographed bridge in the world-are visible from almost every point of elevation in San Francisco.The only cleft in Northern California's 600-mile continental wall,for years this mile-wide strait was considered unbridgeable.As much an architectural as an engineering feat,the Golden Gate took only 52 months to design and build,and was opened in 1937.Designed by Joseph Strauss,it was the first really massive suspension bridge,with a span of 4200ft,and until 1959 ranked as the world's longest.It connects the city at its northwesterly point on the peninsula to Marin County and Northern California,rendering the hitherto essential ferry crossing redundant,and was designed to withstand winds of up to a hundred miles an hour and to swing as much as 27ft.