For real historical locations--London Bridge, the Cheshire Cheese, St. Martin-in-the-Fields, the Fire Courts, Newgate--I have a few maps on hand.
These include the interactive map of early modern London ("The Agas Map") from 1633 and Walter George Bell's 1920 map of the Great Fire of 1666.
But of course it is Lucy's world that is harder to keep straight. Where does Master Hargrave live? Where is Aubrey's printing shop? Where was Mr. Whitby pushed in front of the horse? How long will it take Lucy to walk from Duncan's jail on Fleet Street to the nonconformist burial ground in Bunhill Fields? And when Lucy walks towards Smithfield, will she remember where a murder occurred in an earlier book?
This weekend it occurred to me to create my own master map--Lucy's London--for me to remember where every event occurred in Lucy's life. Using photocopies of the Agas Map (1633) and using Bell as a reference, I was able to develop my own map on which I could color in the area destroyed by the Great Fire and write in all my events for reference. The final result, shown here on my dining room table, is about 5' x 2.5'.
I do, after all, have a book to write. But working on this map gave me an enormous appreciation for the intricate nature of the maps that Agas and Bell created, and deepened my understanding just that much more of the fascinating world of early modern London.