How does the Louvre protect the Mona Lisa? Why did Napoleon commission a painting full of lies? Museum Secrets travels to the world's most famous museums in search of weird, wonderful, amazing and fascinating stories connected with both the well-known and the more obscure exhibits held in their collections. From new revelations on the Mona Lisa, the Sistine Chapel and the golden mask of King Tutankhamun to the mysterious 'tank room' of Britain's Natural History Museum, this series combines surprising revelations about things we recognize with amazing revelations about things we've never seen before.