The famous photo graced the cover of the Fab Four's "Abbey Road," the last album recorded together, and shows the bandmates walking purposefully across the zebra-striped asphalt.
It remains one of music's best-known album covers, endlessly imitated and parodied. Although the shoot itself only took a few minutes, so carefully studied was the cover for signs and symbolism that some die-hard fans came to the conclusion that Paul McCartney - who appears barefoot and out of step with the rest - had secretly died.
McCartney himself made fun of the bizarre conspiracy in the title of his 1993 concert album, "Paul is Live." Conspiracies aside, the ease with which fans can imitate the scene has drawn throngs of tourists to the site every day, turning the street into "a shrine to the Beatles," said Richard Porter, who owns the nearby Beatles Coffee Shop and organized Saturday's event.
Crowds spilled into the street, cameramen jostled for angles, and exasperated drivers honked their horns.
"I didn't expect so many people to be here," said German visitor Tschale Haas, 50, who was dressed in a Sgt. Pepper jacket.
Abbey Road, which cuts through London's well-to-do neighborhood of St. John's Wood, is home to the eponymous studios where the group recorded much of its work.
The group decided to shoot the photograph in August 1969 while recording music for the last time together. For the shot, photographer Iain Macmillan stood on a stepladder and police held up traffic while the Beatles walked back and forth across the street.
The enduring popularity of the site has caused headaches for local authorities, who have had to move the Abbey Road street sign up out of reach to prevent theft and repaint the wall every three months to hide fans' graffiti.
