This week's picture that can be seen for nothing is Doll's House by Patrick Hughes (1993, oil on board). Since 1964, Hughes (who describes himself as a surrealist) has concentrated on three-dimensional relief paintings, usually with an uninhabited , architectural subject - rows of brightly lit night-time skyscrapers , or empty interiors, all walls and windows. These appear to leap out at the viewer in a most disconcerting manner, although only some are actual reliefs: others just appear to be. Con fused? You may be, but that isn't the artist's intention - Hughes is more interested in exploring the nature of perception and in "clarifying our relationship with reality". (Riverside Studios, W6, 081-741 2251, to 31 Jan; Sun 12-10, Mon-Sat 10-11; free.