It may be of interest to describe examples of small round buildings found in exploring Roman forts in this country, adding for comparison notes on others recorded in connexion with forts on the German Limes ; for in many cases the purpose of these buildings has been misunderstood, and in some cases the misunderstanding appears still to persist. The buildings in question are generally about 15-20 feet in internal diameter, and they either stand close beside the bath-buildings of the fort to which they belong, or form part of these buildings. In the last century, when bath-buildings of this kind were habitually described- as ‘villas’ and mistaken for official residences, the circular structures were often described as temples or shrines. But this theory has never been borne out by the discovery of altars, inscriptions, votive objects, or anything whatever pointing to a religious function ; and, on the other hand, even apart from the now universally recognised purpose of the bath-houses with which they are associated, finds have been made in the round buildings themselves pointing towards their use as baths.