According to Wikipedia, the Plan of Saint Gall "is the only surviving major architectural drawing from the roughly 700-year period between the fall of the Western Roman Empire and the 13th century. It is considered a national treasure of Switzerland and remains a significant object of interest among modern scholars, architects, artists and draftspeople for its uniqueness, its beauty, and the insights it provides into medieval culture. "

And what is the Plan of Saint Gall? The same article states, "it depicts an entire Benedictine monastic compound, including church, houses, stables, kitchens, workshops, brewery, infirmary, and a special building for bloodletting." Follow the link here to acces an image of this stunning piece of medieval history.