13 Little Blue Envelopes is set across various European cities, each providing a backdrop that contributes to Ginny’s adventures and personal growth. Ginny visits London, England; Edinburgh, Scotland; Rome, Italy; Paris, France; Amsterdam, Netherlands; Copenhagen, Denmark; and Corfu, Greece. Ginny compares and contrasts aspects of the cities with one another and with cities in the United States, describing the cultural and architectural differences she observes.

Ginny traverses the United Kingdom, made up of England, Scotland, Wales, and Northern Ireland, as she travels between London, the capital of the UK and England, and Edinburgh, the capital of Scotland. Off the northwest coast of mainland Europe, the UK is the homeland of numerous major contributions to the arts, including playwright William Shakespeare and authors Charles Dickens and J. R. R. Tolkien. Additionally, because of the long historical presence of these European countries, architecture is often regionally unique, particularly in comparison to US cities. London, for example, is particularly diverse architecturally, as events such as the Blitz and the Great Fire of London in 1666 have left some historical buildings while requiring reconstruction in other areas time and time again. Outside the UK, cities like Corfu, Greece, offer a much different aesthetic and culture for Ginny to explore.