Recent decades have seen many Romano-Celtic temples excavated in Britain, as a consequence of which evidence has accumulated which challenges the present consensus that they generally had surrounding porticos open to the weather. This interpretation is presented in most standard works on Roman Britain; for example, Professor S. S. Frere has written in Britannia: ‘In the civil zone, the majority [of cults] had much smaller temples of the Romano-Celtic type, where the small square shrine is surrounded by a square portico or cloister’. The same opinion can be traced back through the writings of Sir Ian Richmond and R. G. Collingwood to those of Haverfield. It stems ultimately from nineteenth-century studies in France and Germany, such as those of Fontenay, which anticipated the full presentation of the theory in Lehner's classic survey of Gallo-Roman temples. So far as English studies were concerned, the definitive statement was made in 1928 by the then Dr. Mortimer Wheeler. Among subsequent writers, only Penn and Goodchild and Kirk have expressed strong reservations. This paper seeks to review all the evidence available from Britain on this subject, as a result of which it is suggested that, contrary to previous opinions, the great majority of such temples had enclosed surrounding ambulatories. In the early stages of the discussion, only material from Britain has been considered. This has involved omitting any evidence from pictorial representations or upstanding structures, since neither category of evidence is represented in this province; discussion is focused entirely on the interpretation of excavated remains rarely exceeding a metre in height.