The Hollywood sign - nine giant white letters overlooking an LA district packed with film studios - deserves an epithet that is often misused: icon. For nearly a century, the sight of it has definitively said to those hoping to make their fortune in film: you're here; your dreams are in sight. Perched on Mount Lee in Griffith Park, it hovers above Hollywood, floating like an on-screen caption in a movie starring everyone below.

Fittingly, for a structure representing the flamboyant, boom-and-bust film industry, the sign has a chaotic history. It was erected in 1923 to advertise Hollywoodland, a residential development to be built on steep, rocky terrain at the top of Beachwood Canyon. The huge letters were festooned with lights, flashing in sequence: HOLLY… WOOD… LAND.

The 1992 biopic Chaplin has a scene in which Charlie Chaplin lolls on the sign in the mid-1920s, wondering if 'talkies' would catch on - they already had. People turn to cheap escapism in hard times, so although the Wall Street Crash of 1929 forced the construction of houses near the sign to pause, Hollywood boomed as Hollywoodland stalled. The meaning of the sign began to change.

Hefner convinced nine rich locals to sponsor a letter. Andy Williams paid for W, Alice Cooper funded a new O and Hefner himself bankrolled the Y.

The sign's status as a totem of hopes fulfilled and dashed was cemented in tragic circumstances on 18th September 1932. Struggling actress Peg Entwistle clambered up the craggy hill, scaled the H and jumped to her death, her choice of location bringing her the immortality that her acting never could.

In 1949, the site was taken over by the Hollywood Chamber of Commerce, and the last four letters were junked. The sign finally said HOLLYWOOD, yet the next few decades saw it slide into disrepair, and, by 1978, it was a sad eyesore. As memorably shown in Ben Affleck's 1970s-set Argo, three letters had collapsed, with the others on their way, thanks to termites, weathering and, in the case of the second L, arson.

Only one man seemed to care: suave Turnbull & Asser devotee Hugh Hefner, who hosted a fundraising shindig on 29th June 1978. He convinced nine rich locals to cough up $27,777 each to sponsor a letter. Andy Williams paid for a replacement W, with Alice Cooper funding a new O. Hefner bankrolled the Y.

A spectacular light show on 31 December 1999 placed the robust new sign at the heart of the global millennium party. In 2010, however, it needed saving again when the adjacent Cahuenga Peak was mooted as a real-estate development. Once more, Hugh Hefner - whose romantic attachment to the sign transcends the fact that you can’t actually see it from the Playboy Mansion - stepped in. Of the $11.7m donated by stars, film companies and thousands of LA residents to secure the land, Hugh paid a hefty $1m.

Tourists today are dismayed that they can't touch the sign to see if any Tinseltown sparkle will rub off: it's behind a fence and closely patrolled. They must gaze from afar. But as Hefner said at his 1978 party: 'Hollywood is the city of dreams.' Perhaps it's fitting that the icon of those dreams is just out of reach.