IN THE 55 years since its birth as a single hamburger stand in San Bernardino, California, McDonald's has grown into the world's largest restaurant chain. Today, there are more than 20,000 McDonald's restaurants in 100 countries, and those trademark golden arches are as recognised in Beijing as they are in Boston. Naturally much has changed at your own neighbourhood McDonald's, but in the Los Angeles suburb of Downey, visitors from all over the globe can still get a taste of those early days at the oldest operating McDonald's. Opened in August 1953 at the southwest corner of Florence and Lakewood, this was the third franchise licensed by brothers Richard (Dick) and Maurice (Mac) McDonald. Fifty years later, it's still packing them in, derailed only once by forces even more powerful than the laws of supply and demand - the Northride Earthquake of 1994. Known locally as the historic McDonald's, the red-and-white tiled building is truly hard to miss, thanks to the 20-metre golden arch neon sign featuring Speedee, a cartoon chef with a hamburger for a head and pumping neon legs symbolising fast, efficient service. In keeping with its time, 1950s rock 'n' roll music pours out from the squat, angle-roofed structure that appears to be pinned to the asphalt by a primitive pair of those ubiquitous arches. A single, old-fashioned menu board suspended above the spotless, stainless-steel interior tells patrons what their choices are as they queue up in front of six, sliding aluminium window counters. Not surprisingly, the most popular selection - for nostalgia seekers and bargain hunters alike - is the Original All-American Meal: a hamburger, fries, and a shake for only US$3.24 (HK$25). Such hallowed ground, of course, could not be left uncommemorated. Adjacent to the original building, therefore, is the Museum of McDonald's History, where a series of display windows - supplemented by a continuously running video - chronicle the growth of the McDonald's empire. 'It is difficult to realise that it all started with the simple idea of serving customers what they wanted: takeout hamburgers, French fries, and soft drinks at value prices with fast, friendly service,'' wrote an ailing Dick McDonald on the occasion of the grand reopening in 1996. What the McDonald brothers had realised, however, was that life in post-war America was about to change dramatically due to the phenomenal growth in personal transportation - the family car. The new on-the-go lifestyle brought with it an appetite for minimalist food and minimised downtimes. Speed was now the name of the game and the McDonald's were among the original pace-setters, converting a popular sit-down barbecue restaurant into a drive-in with female carhops. By paring their menu from 25 items to just nine, they reduced the average food preparation time from 20 minutes to 30 seconds. When it became obvious that the carhops couldn't deliver the food as fast as the new assembly-line kitchen could prepare it, they were eliminated in favour of walk-up counters. The simple 18-cent hamburger upon which the McDonald brothers staked their future was an instant favourite - not just with teenagers out joy-riding, but with harried mothers, frugal office workers and even church groups. It would be the milkshake, however, that would alter the course of dining history. When they placed an order for an unprecedented eight blending machines in 1954, Multimixer salesman Ray Kroc flew out from Chicago to see what was, well, shaking. Convinced that the McDonald's had a real gold mine under their gimmicky yellow arches, Kroc tried persuading them to go national. But the McDonald's were sceptical, doubting that their quintessentially California concept would survive in colder climates. So Kroc took the financial initiative, forging a licensing deal that would last until 1961, when he bought the McDonald's out for US$2.7 million - an even million for each brother, after what they would have to pay in taxes. Happily, it was a story that would be missing one page. Because the McDonald's in Downey was independently owned, it was not part of the 1961 buyout. Seeing no reason to tamper with success, owners Roger Williams and Bud Landon kept their little gold mine just the way it was. By the time they finally sold in 1990, their McDonald's had become the great-granddaddy of them all. Wisely, the McDonald's Corporation decided to leave it just the way it had always been so that fast-food aficionados from all over the world can still walk up and sink their teeth into an authentic piece of American culture.