Milecastle 23

Milecastle 23 was a long-axis milecastle. The gateway type is unknown, though long-axis milecastles were thought to have been constructed by the Legio VI Victrix who were based in Eboracum (York). The milecastle measured 15.24 m across, and had broad east and west walls (the curtain wall at this point was also broad gauge). The width of the south wall is unknown. The ditch at the point corresponding to the milecastle's north gate undergoes a slight change in profile in the bottom. Also, there is an 8 m gap in the upcast mound at the same point. These features indicate the existence of a causeway, later removed. There was also evidence of an equivalent causeway across the vallum, and gaps in…