Museum Ludwig, Cologne

This extraordinary museum houses works from most of the key 20th-century movements, from pop art to the Russian avant garde and American abstract artists. But it is the holding of 864 works by Picasso for which it is most famous. This is the world’s third-largest collection of his works after the Picasso museums in Paris and Barcelona. All the key phases of the artist’s paintings are represented, and there is also a large collection of drawings and graphics, ceramics and sculptures, including the plaster Woman with Pram (1950) and the monumental head of his lover of the Thirties and Forties, Dora Maar. Key paintings normally on display include Harlequin (1923) and Woman with Artichoke (1941).