The sea fog of San Francisco is an old friend to the people who live there. When warm air from the Pacific blows across the cool waters of the California current, it forms as a low-lying cloud, lingering close to the ground. An anomaly in winter when the ocean cools down, the fog is an almost permanent feature of the San Francisco summer.

And, despite a preceding spell of unbroken August sunshine, such was the weather on the day of my walk: a now fogged and chilly route that traced an anti-clockwise arc along the waterfront, past newly developed offices and condominiums, through gaudy tourist attractions, then deep into undeveloped tracts of wilderness.

My girlfriend Ali and I began our journey at the Ferry Building, a grand galleria punctuated by a clock tower, which was the city’s main transportation hub until the Golden Gate and Bay bridges were built in the 1930s. But before embarking on what was likely to be a five-hour endeavour, we needed fortification. We stopped by the Acme Bread Company and ordered two robust cheese sandwiches.

Departing from the Ferry Building, we walked north along the Embarcadero, a wide waterfront roadway that marks the city’s eastern edge. To our right, massive piers jutted into the bay. Once busy industrial docks, the piers now house high-end restaurants and the sleek offices of companies such as Bloomberg. To our left, vintage streetcars rattled by. Out of use for decades, the fleet of elegant mid-20th-century rail cars was recently restored and put back into service.

From the city’s northeast corner protrudes Pier 39, a cacophonous assemblage of arcades, souvenir shops and eateries. It is redeemed only by its famous furry inhabitants – an enormous colony of sea lions. Occupying a few dozen floating docks, the 500 sea lions bark and preen in an malodorous and noisy throng. We joined the onlookers for a moment, then moved on to escape the pong.

Continuing past Pier 39, we quickly bypassed two of San Francisco’s other tourist traps. Fisherman’s Wharf, once a working dock where the city’s fleet hauled in their catch, today is a jumble of novelty shops. Overlooking the Wharf is Ghirardelli Square, a hulking brick former chocolate factory also overwhelmed by cheap stores and chain restaurants.

A more authentic glimpse of life in the city came at a nearby beach on the bay. There, a group of athletes donned wetsuits and braved the frigid Pacific Ocean waters. This being California, another beach dweller was practising yoga, doing a handstand in the sand.

We walked on to Fort Mason, a decommissioned army base. Part of the vast military infrastructure built to protect the Bay area during the two world wars, Fort Mason is now home to artist studios, vegetarian restaurants and a progressive think-tank called The Long Now Foundation.

Ali and I had travelled much of this route a few weeks before, when we ran the San Francisco Half Marathon. Retracing our steps at a slower pace, I had time to notice aloe plants, pines and eucalyptus trees, as well as pelicans, black-bellied plovers and snowy egrets.

Between Fort Mason and the Golden Gate Bridge lies Crissy Field, another San Francisco relic that has been successfully reinvented. The site of the 1915 Panama-Pacific International Exposition, Crissy Field then became the airfield for the Presidio army base. In the 1990s, the site was decommissioned, cleaned up and turned into a public park. Couples were out jogging, flying kites and walking dogs. Families picnicked on top of concrete bunkers overgrown with grass.

The Golden Gate Bridge now came fully into view. Beneath it, a regatta was under way. Dozens of sailboats were bunched together, keeling in the stiff wind as they manoeuvred around orange buoys. It was clearly the right weather for sailing, but the cold was biting.

Two hours of walking had worn us down, and we paused at The Warming Hut, a café at the foot of the bridge. For a moment, the sun peeked through the clouds. Two cups of tea and one peanut butter cookie later, we resumed the journey.

A steep wooden staircase beckoned upwards to the bridge. On the pedestrian walkway, 200ft above the water, the Pacific and the city skyline spread out before us. Above our heads, the bridge’s two orange towers were lost in slate-grey fog.

The two miles of trails after the Golden Gate Bridge were uneventful but beautiful. After meandering through another army base turned public park, we passed Sea Cliff, San Francisco’s most exclusive neighbourhood. In a reminder of the recession, an inordinate number of mansions were for sale.

Finally we headed south along the western edge of the peninsula, through the wild and undeveloped Lands End. Emerging from the thickets, our final destination came into sight: the Cliff House, a restaurant perched on a precarious overhang, which has been serving locals since 1863.

Our walk had taken us 9.5 miles along San Francisco’s coastline, and with dusk an hour away, we felt deserving of a drink. I ordered a gin martini, and Ali got the Cliff House’s famous pear martini. We split a plate of oysters.

Our bartender, with greying hair and mutton chop sideburns, began telling us about the various incarnations of the Cliff House over the decades. I found myself peering south, where Ocean Beach extends for three miles, the city’s last great swath of undeveloped waterfront. Behind us, the Pacific stretched into the distance, silver and calm. As the light dimmed, the horizon became indistinct and eventually merged with the fog, which still had not lifted.

David Gelles is a reporter in the FT’s San Francisco bureau

For more city walks, including a tour of Washington’s scandals, go to www.ft.com/walks

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Food & Drink

Acme Bread Company, (415) 288-2978, www.ferrybuildingmarketplace.com; The Warming Hut, (415) 561-3040; The Cliff House, (415) 386-3330, www.cliffhouse.com