San Francisco Landmarks
The Golden Gate Bridge is one of the world's most widely recognized structures. It is a defining icon of the Bay Area, and is arguably the structure most prominently associated with San Francisco.
Historically, it is significant in that it completed the final link in a national highway system connecting Canada and Mexico while providing enough clearance above the water's surface to allow the largest ships to enter the San Francisco Bay.
Art Deco and Art Moderne architecture were combined with advanced suspension-bridge-building technology to create a spectacular bridge structure designed to compliment [sic] its natural surroundings.
The Golden Gate Bridge stands today as a timeless "environmental sculpture" that is both a work of art and a vital, indispensable, functioning element of California and America's highway infrastructure. It is the grand entrance gate to one of the world's great cities, and the western gateway to America.
Source: Planning Commission Resolution No. 14754 dated 17 December 1998.

The Golden Gate Bridge is also California Landmark #974.