If contemporary art is your thing, the Zoo Art Fair, which returns to the Royal Academy for its fifth season, is a must-see. Zoo is where the avant-garde come out to play, and players including Saatchi, Tracey Emin and the Chapman Brothers have previously joined the throng to buy, browse and size up their successors. International presence among this year's 57 stalls has doubled, with participants including New York's Renwick Gallery and Milan's Francesca Minini, while Limoncello, Paradise Row and many others represent the London scene. Indulge your artistic fancies with everything ranging from installations and videos to photography, painting and sculpture.