It is visited by 4.5 million people from all over the world each year, it is free and it is currently celebrating its 250th anniversary. Back in 1753 the British Museum was founded following the bequest of Sir Hans Sloane's own collection of antiquities to the British nation. The inspired idea to bring together a collection of artefacts, paintings, books and curiosities for everybody to enjoy free of charge was 'an extraordinary experiment in public...