|Prabable road: E (13) to Ffridd
SSW (13) to Penrhos
NNW (11) to St Asaph
Situated upon a low gravel ridge on the valley floor beside the river Clwyd about 220 yards (c.200 m) west of the Roman road between Caer Gai and St. Asaph, this trapezoidal fort was discovered from the air by A.C. and E. Waddelove in 1981 in the fields of Tyn-y-Wern Farm, Ruthin. Two adjoining sides of the enclosure measure around 410 ft. in length, the others are about 610 ft. and 250 ft. long (c.125, 185 & 77 m), enclosing an area of about 4½ acres (c.1.8 ha). The size is typical of a Roman fort purposely built to house a 500-strong cohort of auxiliary infantry.