There’s something about a bridge. Whether it’s an ancient stone arch over a stream or a 19th-century wonder like the Roeblings’ Brooklyn beauty or a modern, mile-long steel behemoth with towers that rise hundreds of feet into the air, a bridge is the most practical and the most evocative of structures. A bridge takes us places; a bridge connects places. And sometimes, a single bridge can help to define places.

Take the Golden Gate Bridge. With its immediately recognizable “international orange” — not golden — color, its slender, arcing span and its open, stepped towers so often rising dreamlike above the thick fog that courses through the Gate into the bay on summer afternoons, the Art Deco-inflected masterpiece literally connects San Francisco with Marin County to the north and (with perhaps even greater impact) symbolically connects the entire Bay Area with the wild blue Pacific yonder.

Much like its older, statelier limestone and granite cousin 3,000 miles to the east in Brooklyn, the Golden Gate Bridge seems to have always been there. It’s almost impossible, now, to imagine the lower East River or the Golden Gate itself without those visionary, boldly executed marvels.

Like all great architecture, the Golden Gate Bridge doesn’t feel at all like an imposition on its environment. Instead — and at the risk of incurring the wrath of hardcore nature lovers everywhere — the bridge in some very elemental ways manages to enhance its environment. Powerful, graceful, uniting two distinct (town and country) regions of the nation’s most populous state, it is more than an elegant contrivance of cement and steel. As anyone who has walked, ridden a bike or driven across the thrilling structure — or passed beneath it on a boat, through the intense, choppy, frigid waters — can attest, the Golden Gate Bridge is a grand, audacious, beautiful idea brought to life in concrete and steel.

Liz Ronk, who edited this gallery, is the Photo Editor for LIFE.com. Follow her on Twitter @lizabethronk.