Beatles fans came together near London's Abbey Road Studios on Thursday to mark the 50th anniversary of the band making one of the most iconic album covers of all time.

The picture of Britain's legendary Fab Four walking over the pedestrian crossing outside the studios was shot for the sleeve of "Abbey Road", their final studio album.

The shot of John Lennon leading band mates Ringo Starr, Paul McCartney and George Harrison across Abbey Road is instantly recognised all over the world.

The idea stemmed from a sketch by McCartney of stickmen on the zebra crossing.

The picture was taken at around 11:35 am on August 8, 1969 by Scottish photographer Iain Macmillan.

The time of day was chosen to avoid fans, who knew that the band typically turned up at the studios in the mid-afternoon.

Macmillan stood on a stepladder in the street, while a policeman stopped the traffic.

Macmillan took six frames, of which the fifth one was used -- the only one with the band stepping in unison.

The photo shoot was over in about 10 minutes.

CONSPIRACY THEORIES

The album's final recordings were done 12 days later on August 20.

"Abbey Road" was released on September 26 -- six days after Lennon privately told his band mates he was quitting the group.

Recorded after the troubled "Let It Be" album, which was eventually released on May 8, 1970, "Abbey Road" was made in a much happier atmosphere.

The album contained 17 tracks, including Harrison's "Something" and "Here Comes the Sun", Starr's "Octopus's Garden", Lennon's "Come Together", and the closing medley of scraps of unfinished songs largely by McCartney.

The front cover, unusually, did not feature the name of the band or the album. However, the record, and its sleeve became cherished classics.

The cover also fuelled the "Paul Is Dead" conspiracy theory.

Some people believed that McCartney having a cigarette in his right hand despite being left-handed proved he was an imposter, and saw hidden messages in him walking out of step with the others and being barefoot.

PILGRIMAGE SITE

Abbey Road Studios is in St. John's Wood, a wealthy residential part of northwest London.

Built in 1829, it was originally a nine-bedroomed house before being turned into the world's first purpose-built recording studio, which opened in 1931.

Initially a venue for classical recordings, it branched out to jazz, big bands and eventually rock and roll.

Some 190 of The Beatles' 210 songs were recorded there, and McCartney's London home is just around the corner.

It has drawn Beatles pilgrims from across the world ever since, with countless fans having walked over the zebra crossing, replicating the picture.

The crossing is also continuously live-streamed on the studio's website.

The studio, normally closed to the public, has given up trying to deter visitors from scrawling graffiti on the white garden wall and now encourages it, painting over the messages several times a year.

The crossing gained Grade II protected status in 2010, meaning that it is recognised as nationally important and of special interest.