Ale, Caesar! Romans and Caledonian tribes went to pub together
http://www.scotsman.com/lifestyle/heritage/ale-caesar-romans-and-caledonian-tribes-went-to-pub-together-1-2514282
Maybe I am just dense. I read the entire article at your link, but I did not see anything there to indicate that the natives were coming to the “pub” that is described. Perhaps the building was just a well-designed mess hall.