The Caer Gai Roman Fort is located on a spur in the valley of the Dee (Afon Dyfrdwy) overlooking the river from its north bank, the Caergai fort is square in plan, each side measuring about 128m, and covers an area of 4½ acres (1.7 ha). The fort was furnished with timber buildings never rebuilt in stone and was occupied from c.75AD until c.130. Caer Gai is a Roman auxiliary fort capable of housing a garrison in excess of 500 soldiers.

The Caergai farmhouse occupies the north corner of the fort and has destroyed most of the north corner-angle. A spring which probably served the Roman soldiers lies about 200 feet outside the western corner-angle.

In 1865 a number of urns of coarse grey ware were uncovered in the field named Cae Dentir to the immediate north-east of the fort, each of which contained the ashes and burnt bones of human cremations. In this same field in 1885 the foundations of a small (9 x 9 ft) square timber building were uncovered, in the centre of which was square pit containing sherds of samian pottery and other decorated wares. Lying on its side over the foundation trench of this building was a block of red sandstone measuring 30 x 23 x 10 inches (c.76 x 58 x 25 cm) and bearing the only Latin inscription to be found on the site, fortunately naming one of the occupying regiments (vide RIB 418 infra).

RIB 418 - Dedication by Julius, son of Gavero

Julius, son of Gavero, soldier of the First Cohort of Nervians, (set this up).


No commentary.

There are two Roman practice works nearby at Rhyd Sarn (SH8527).

References for Caer Gai

  • Military Aspects of Roman Wales by Prof. F. Haverfield (London 1910; pp.43-46);
  • Air Reconnaissance in Britain, 1958-1960 by J.K. St. Joseph in J.R.S. li (1961) p.130;
  • The Roman Inscriptions of Britain by R.G. Collingwood and R.P. Wright (Oxford 1965); 
  • Air Reconnaissance in Britain, 1973-76 by J.K. St. Joseph in J.R.S. lxvii (1977) p.151;

Map References for Caer Gai

NGRef: SH8731 OSMap: LR124/125, OL18

OS National Grid Reference: SH877314
Dimensions: c.420 x 420 ft (c.128 x 128 m)
Area: c.4½ acres (c.1.7 ha)

Roman Roads near Caer Gai

SW (11) to Brithdir (Gwynedd) NE (5) to Llanfor (Gwynedd) Margary 66b: SW (2.5) to Rhyd Sarn

Sites near Caer Gai Roman Fort