Cthulhu Britannica: London (2015)

From the publisher:

London in the 1920s is the greatest city in the world, a vibrant melting pot of history and culture at the heart of the British Empire. But underneath the powerhouse of the City lie millennia of history, from the well-documented paths of Roman Londinium to darker antediluvian secrets veiled from modern eyes. London sits atop its history: an ancient swampland that was itself once an even-more-ancient sea-bed. Who knows what secrets lie buried?

The Cthulhu Britannica: London boxed set comprises:
- The Investigator's Guide to London
- The Keeper's Guide to London
- Adventures in Mythos London
- Six sheets of beautifully designed handouts
- Four poster maps, including a beautifully illustrated Macdonald Gill map of Central London