British Library

The Sir John Ritblat Treasures Gallery One free room in London that covers more of the history of writing than most whole museums. Cases are arranged by theme, from sacred texts and historical documents to literature, maps and art, so a medieval manuscript, a copy of Magna Carta and Leonardo da Vinci's notebooks can sit a few steps apart. No booking is needed, which makes it easy to drop in between trains at King's Cross and St Pancras next door. The library rotates items off display for conservation and lends some to other institutions, so contact it in advance if you are traveling for one particular book.