Mithraeum of Caernarfon

George C. Boon writes me: ’In August, 1959, a Mithraeum 48 by 21 1/2 ft. was excavated 150 yds. E. of the Roman fort of Segontium (Caernarvon, north Wales) by the National Museum of Wales on behalf of the Ministry of Works. The building, which occupied a site previously utilized probably in Flavian times, lay almost at the bottom of a small, marshy valley, parallel to and partly set into the building, being aligned 300 E. of N.
The Mithraeum was of rude construction, employing mostly undressed beach-boulders for the walls, and had a roof of large, square, local slates. It possessed a narthex, 6 by 18 ft…