In addition to providing an in-depth description of various locations, the Baedeker guide books provide a mine of information for historical researchers.  Because they were so complete, the guides offer an in-depth portrait of a place captured at a particular time, and include information on then-current details of social history and customs, urban development, arts, archaeology, entertainment, sport, and tourism.  Whether for travel by plane, foot, or armchair, Baedeker Guide Books were considered essential knowledge for any journey.