The History of Mithraea in Britain

How many Mithraea were built or thought to have been built? We absolutely have no idea. However, what we do know is that there were lots of them. At the latest count, I think about 420 have been identified as surviving in hall or in part across the Roman Empire. But there would have been many, many more than that. There are over a thousand inscriptions to Mithraus and Norn across the Empire. 700 depictions of this central scene of the bull killing in the cave, from across the empire. These temples are everywhere - but relatively few you find in the countryside. It does seem to be a cult that's focused where there are significant concentrations of people.