Type: Vexillation Fort, Fort
Situated on the English side of the River Ceiriog opposite Chirk, two overlapping encampments were discovered from the air in July 1975, the western side of the smaller camp overlies the eastern defences of the larger, both of which may be termed "vexillation forts". Sparse dating evidence from the site has led excavators to suggest a tentative occupation period sometime during the mid-first century, and it seems likely that the larger fortress may be related to the initial campaigns of governor Publius Ostorius Scapula against the Deceangi of North Wales c.A.D.47. The large fortress was succeeded by a smaller fort, possibly during the Welsh campaigns of governor Sextus Julius Frontinus c.A.D.75.
|SJ306370||c.1,585 x 1,160 ft
(c.483 x 254 m)
The larger of the two enclosures is an irregular quadrilateral, with no two sides or angles quite the same; the north side measures 1,080 feet in length, the south side 1,240 feet, the east 1,640 feet, and the west 1,530 feet (respectively, c. 329, 378, 500 & 466 metres). The defences consist of a double ditch system, the outer ditch much more substantial then the inner, enclosing an area of around 42 acres (17 ha). The north-western corner-angle has been lost to erosion by the Afon Ceiriog. There are four gateways, all protected by tutulus outworks, those to north and south are centrally placed in their sides, those in the eastern and western defences are off-set towards the north; the fortress therefore faced north across the Ceiriog. There is another set of univallate defences attached to the southern end of the camp which annexes a further 3½ acres (c.1.4 ha).
|SJ307369||800+ x 750 ft
(244+ x 228 m)
The smaller fort is defined by a narrow defensive ditch, of which the whole west side, measuring some 750 feet (c.228 m), the two western corner-angles, and attached, an 800 foot (c.244 m) length of the south side and a 640 foot (c.195 m) length of the north side, have been traced by aerial photography; the eastern defences are lost, due to erosion of the minor valley on this side. There is an outer defensive work to the west, where a wide ditch set at least 100 feet (c.30 m) outside the inner defences has a staggered entrance opposite a gateway set centrally in the inner ditch. There is a gap in the southern defences as if for a gatewy about 500 feet (c.152 m) from the western corner which, if centrally placed, would give an east-west dimension of about 1,000 feet (c.305 m). The area enclosed by the inner defences is at least 14 acres (c.5.7 ha), possibly as much as 17 acres (c.7 ha), which is still rather large to be an ordinary auxiliary fort.