With a career spanning over six decades, Magnum photographer David Hurn is a connoisseur and patron of documentary photography. He has come up with a deliciously simple concept: building a collection of photographs by exchanging his own images for those of other photographers, in particular his Magnum colleagues. Over the years, Hurn has amassed more than 600 prints, dating from the 19th century to the present day. Last year, the entire collection was gifted to the National Museum of Wales, where in September 2017 their inaugural exhibition marked the opening of the museum’s first permanent gallery dedicated to photography. Martin Parr curated an exhibition of swaps with his Magnum colleagues and this was originally shown in 2017 at Photo London. The Martin Parr Foundation will exhibit highlights from this show, including works by Henri Cartier-Bresson, Alec Soth, Elliott Erwitt and Newsha Tavakolian. Photo - Andy Warhol in his "Factory" at Union Square, New York City, USA, 1981 © Thomas Hoepker / Magnum Photos