This collection is composed of architectural notebooks with Davis's handwritten notes and sketches of architectural features of sites in England, Western Europe, Southern Europe, North Africa, the Levant and Turkey. The majority of the notes are on sites in England and France, but other countries include Belgium, the Netherlands, Luxemburg, Germany, Italy, Greece, Croatia, Tunisia, Libya, Egypt, Lebanon, Palestine, and Syria. The focus of Davis's research represented in these notebooks is primarily on structures created during the medieval period: cathedrals, churches, abbeys, castles, mosques, etc., but there are also notes on sites from the Roman period and earlier. Some of the notebooks contain inserted photos of sites, engravings, travel brochures, maps and ephemera. Some of the early notebooks in this collection cover the period during the Second World War in which Davis served with the Hadfield-Spears mobile hospital unit in the Near East, North Africa, and Southern Europe, including notes he took on the mosques of Cairo, the topic of his first book.