Excavations to the east of the Roman fort of Inveresk in 2010 partly uncovered remains of a Mithraeumthe first from Scotland, and the earliest securely dated example from Britain. A large rectangular sunken feature with lateral benches contained two altars buried face down at its north-western end. One was dedicated to Mithras, with iconography of both Mithras (ravens and a torch) and Apollo (griffin, lyre and a probable plectrum) as well as libation vessels. The other was dedicated to Sol, with a frieze above showing the four Seasons. The Sol altar was a dramatic one, with a recess in the rear for a light which would have shone through his pierced rays, eyes, mouth and nose. Remains of an iron rod behind the nose hint at a more complex arrangement to create special visual or acoustic effects. Paint and plaster traces were recorded on both altars. The dedicator, G(aius) Cas(sius) Fla(...), a centurion, may have been in command of the garrison or of a legionary detachment. Stylistic links, especially in letter form, connect the work to sculptors of Legio XX. The stones and pigments are most likely from local sources. little of the setting could be explored but there were traces of a precinct. A pit beside the Mithraeum included a large part of a well-used fineware beaker which represented a deliberate offering. Supplementary material available online (http://journals.cambridge.org/bri) contains detailed descriptions of the altars, observations on the stoneworking technology, lithology and pigment analysis, with extensive illustrations.Inveresk fort is situated on the Firth of Forth east of Edinburgh. It is contemporary with the Antonine Wall (c. AD 140-165), 1 and was well-placed to act as part of a system of coastal defence as well as a supply base and port for the Wall. 2 The environs have yielded the most extensive evidence for extramural activity of any Roman fort in Scotland. 3 There is a large vicus to the east, with a bath house probably associated with a mansio, field systems to east, north and south, burials to the north, and a series of temporary camps to the south and south-east. Yet the Mithraeum was an unexpected discovery during excavations associated with the construction of a replacement cricket pavilion by East Lothian Council within Lewisvale Park. Much of the area is a Scheduled Ancient Monument, and the conditions of Scheduled Monument Consent required the pavilion development to be monitored.The site chosen for the pavilion largely occupied that of its predecessor within a grassed area near the northern edge of the scheduled area (FIG. 1). 4 Located approximately 750 m to the east of the fort on the same low east-west ridge, the current level parkland has been subject to extensive modern landscaping. The overall aspect of the site is to the north where the land slopes down to the Firth of Forth. The monitored topsoil strip commenced on 22 March 2010, and a ditch feature and the Roman altars were revealed that day and the following morning. The remains were excavated between 24 March and 5 Apr...
