article: The works at Nottingham Castle include a chalk portrait of St Anne, sketches of bodies and plants, plus some technical drawings. The artist made only around 20 paintings during his lifetime, including the Mona Lisa and The Last Supper, but left many more drawings. In total, there are almost 600 drawings by da Vinci in the Royal Collection. They were originally bound into a single album, thought to have been acquired in the 17th Century by Charles II. Experts believe Leonardo's drawings are the richest, most wide-ranging and most technically brilliant of any artist. The exhibition is on show at Nottingham Castle Museum and Art Gallery until 9 October.