The big-screen adaptation of Alan Moore's seminal graphic novel is being released on DVD and Blu-ray on 27 July. The launch is to be celebrated with a 3D art instilation down at the skatepark under London's Southbank Centre, as graffiti artist Chu recreates scenes from the film, with running commentary from Watchmen illustrator Dave Gibbons, from 2-5pm on 28 July. The Guardian are counting down to the release with a clip of the film's opening scene, and an introduction by director Zack Snyder: the video will be available from 11.55pm at www.guardian.co.uk/film/watchmen.