SAN FRANCISCO — The day I walked across the Golden Gate Bridge, the sky was as blue as vintage china.

There was no wind, just the slight breeze from traffic. It was pleasantly cool. A few cyclists sped by, a couple of runners, a handful of walkers.

With every step, the orange towers loomed larger.

With every step, I felt smaller, a tiny dot above San Francisco Bay.

Walking the Golden Gate Bridge isn't on everyone's to-do tourist list. But when this city's fabled fog parts for sunshine, it could be one of the most memorable experiences you will ever have.

Opened in 1937, the 1.7-mile orange bridge connecting San Francisco to Marin County is one of the few big bridges in the world that welcome walkers and bicycle traffic.

Unlike Michigan's 5-mile-long Mackinac Bridge, which allows pedestrians only on Labor Day, the Golden Gate span has a dedicated pedestrian/cycle lane.

The celebrity bridge also has its own visitors center, gift shop, gardens and cafe, at the foot of the span on the San Francisco side. From there, it's just a few steps up to the walkway.

Once on the bridge, the incline is steady but not steep.

Tourists usually see the Golden Gate Bridge from below on a tour boat, or by bus, car or bike (see "If you go" box). But standing quietly on the bridge, a walker absorbs both the organic experience of being on the span itself and the sights beyond its cables and steel.

Look down. See the roiling water of San Francisco Bay more than 200 feet below. Look north and east, and see the undulating green of Marin County, melancholy Alcatraz Island and the tidy San Francisco skyline.

At the same time, up close, you can see that each rivet is the size of a salad plate. The orange paint is slightly ocher. The pavement beneath your feet vibrates a bit from the traffic.

More than 1.8 billion vehicles have crossed the Golden Gate Bridge since it opened. Bridge officials don't keep track of how many pedestrians use the bridge, but there can be as many as 6,000 on a busy summer day, says Mary Currie, spokeswoman for the Golden Gate Bridge Highway and Transportation District.

In the early 20th century, San Francisco boomed with dreamers, but ferries were the only way across the Golden Gate straits. Why? Nobody thought it was possible to build an earthquake-proof bridge there.

Then engineer Joseph Strauss and colleagues came up with an idea — a suspension bridge able to move with the wind and anchored securely against peril.

It worked. For 73 years, the Golden Gate Bridge has withstood storms and earthquakes, even the 1989 Loma Prieta quake that cracked the nearby Bay Bridge. It can sway (side to side) 27.7 feet and flex (up and down) 10.8 feet.

Can a pedestrian feel it sway? I tried to. I didn't. But then again, it was a quiet day.

At the bridge's highest point, walkers stand 271 feet above the water, while the Art Deco-style towers loom another 500 feet straight up.

Along the way, I met a bridge painter unrolling a hose and toting pails of International Orange paint.

Is it true that as soon as they finish painting the bridge from one end to the other, they have to start over?

"That makes a good story," he said, laughing.

Although the bridge radiates good nature, it has a dark side. Anyone who walks it will quickly realize that its orange railings are way, way too low for common sense — just 4 feet high. About 24 people commit suicide every year by jumping off the bridge.

Golden Gate Bridge officials have proposed adding metal nets 20 feet below the railings on each side to catch or deter jumpers. The $50 million net idea has been deemed the least intrusive to the architecture while also being effective. It also would allow them to keep the bridge open to pedestrians.

Because final funding has not been approved, there's no start date yet for the bittersweet project, Currie says.

But it would be good to end the bridge's link to sorrow.

I'd wager that for most people, standing atop the Golden Gate makes you glad to be alive, not the opposite.