Type: Practice Work, Industry
|Margary 66b: NE (2.5) to Caergai (Gwynedd)
Margary 66b: SW (8.5) to Brithdir (Gwynedd)
|SH860278||c.255 x 165 ft
(c.78 x 50 m)
The largest of the two known Roman military practice works at Rhyd Sarn measures 255 feet from south-west to north-east by 165 feet transversely (c.78 x 50 m), enclosing an area of just under 1 acre (c.0.39 ha) within a single rampart and ditch which is remarkably well-preserved on the north. The smaller work lies some 700 feet to the west.