You don't need us to tell you that people travel from all over the world to visit London's museums. But while you've probably already plodded round the V&A and gawped at dinosaur skeletons at the Natural History Museum, this guide will introduce you to all the greatest collections, archives and house museums that you've never heard of but won't be able to stop talking about once you visit. From elephant skulls at the Grant Museum to hidden masterpieces at Leighton House and medical memorabilia at St Bart's Hospital, there's more to discover than Egyptian mummies and medieval manuscripts (although those are excellent too).