'Blow-Up', Antonioni's cult film, hit our screens 40 years ago. Robert Nurden goes in search of the places used for filming, from Notting Hill to a neglected park in a little-known corner of south-east London

The oblong patch of rough grass and strip of woodland where Thomas the fashion photographer inadvertently stumbled across canoodling lovers and a grisly murder are still there. The fence has disintegrated, but the wind still hisses through the trees just as it did in the haunting opening sequence of the cult movie Blow-Up, back in 1966.

Down some steep steps lie the tennis courts where the flower children - student extras recruited from nearby Goldsmiths College - acted out a silent game of tennis without a ball. But the simple plaque commemorating the filming in the summer of 1966 has been wrenched away.

Welcome to little-known Maryon Park, Charlton, location for Michelangelo Antonioni's ground-breaking art-house film, whose fans arecelebrating its 40th anniversary. To mark the event, the Photographers' Gallery in London is staging an exhibition of rare images connected with the making of the movie.

Blow-Up, which won the Palme d'Or at the 1967 Cannes Film Festival, is one of the finest evocations of the headiness of London in the Swinging Sixties. David Hemmings, who died in December 2003, played the fashion photographer, who is thought to have been based on David Bailey.

A handful of aficionados are the only ones who know of the unlikely connection this superb film has with a slightly scruffy park in south-east London, once the property of local aristocrat Sir Maryon Wilson. It was here, on the site of one of Charlton's disused sandpits, that the most significant of the outdoor scenes were shot. And the copse where a 24-year-old Hemmings snapped the mysterious goings-on with his zoom lens is still known as the Hanging Wood.

The park is a quarter of a mile south of the Thames barrier, to the west, another disused quarry now houses Charlton Athletic's football ground, The Valley. Maryon Park is not to be confused with nearby Maryon Wilson Park, whose main attraction is its small zoo. One theory is that Antonioni chose this unfashionable spot because it had a unique confluence of ley lines. A more likely explanation is that it was quiet.

In more recent years an old park-keeper has reminisced about the making of Blow-Up. He had been dismayed when Antonioni ordered some trees to be covered in black and green paint.

The White Horse, the pub on the A206 where actors and crew consumed vast amounts of alcohol when rain stopped filming, is still there. But the antique shop in Cleveley Close, SE7, where Hemmings dropped in to make an impulse buy of an aircraft propeller, has gone.

Switch to west London for the scenes involving the Yardbirds, Peter Bowles, glamorous models - Sarah Miles and Jane Birkin among them - and the studio where Hemmings blew up those grainy exposures from the Hanging Wood scenes. Most of these sequences were shot in Notting Hill. For the outside shots, Antonioni used two particular locations - 77 Pottery Lane, W11; and 49 Princes Place, W11, both still standing.

Perhaps, though, it is right that the locations for a classic film exploring the paradoxes of reality and illusion should be out of the public eye and off the tourist map. Come to think of it, a murky, wind-blown public place in south-east London and a couple of back streets in Notting Hill are just about right.

The final venue on your Blow-Up tour is the Photographers' Gallery, near Leicester Square in central London, to see the anniversary exhibition. It closes next Sunday, so hurry to catch it. The show cleverly explores the links between photography, film and painting, which were weaving a complex web through the visual culture of London in the mid-1960s.

For the first time since the movie's production, the paintings of Ian Stephenson, which were a powerful influence on Antonioni when he first came to London to make the film, have been brought together with some rare photographs by Don McCullin, the legendary Vietnam War photographer. The exhibition centres on 12 photographs taken by McCullin for Antonioni of the park scene, as if through the protagonist's camera.

To reach Maryon Park, take a train from London Bridge to either Charlton or Woolwich Dockyard: the park entrance is off Woolwich Road, the A206. For Notting Hill locations, take the tube to Holland Park - and an 'A-Z'. The Photographers' Gallery is at 5 Great Newport Street, London WC2 (020-7831 1772; photonet.org.uk)