Pen Llystyn Roman Fort

Flavian Auxiliary Fort (AD 69–96)

The Roman military settlement at Pen Llystyn lies on the Roman road between Caernarfon and Tomen y Mur at a strategically important position between the Lleyn Peninsula and the Snowdonia Mountains. It was the subject of extensive rescue excavations between 1954 and 1962 (Hogg 1959; 1969) when much of the internal arrangement of buildings was recorded prior to the fort’s almost complete removal by gravel extraction operations.

The settlement was centred on an auxiliary fort established in the late AD 70s that continued in use until about AD 90 when it appears to have been deliberately burnt down by its garrison and abandoned. A smaller fortlet was later established in the northern corner in the first quarter of the second century, but this was abandoned around 125 AD.

The road alters heading from south-south-east to east-south-east, about a kilometer to the south of the site. The fort faces south-west across the river valley and was obviously sited to police the Ganganorum Promontorium (Lleyn Penninsula), possibly the home of the Gangani tribe.

Unfortunately, the site is now almost completely lost due to gravel-working.

There is a temporary camp on the opposite bank of the Afon Dwyfach at Derwydd-bach Farm (SH4745), just to the north-east, and a substantial Roman building at Tremadog (SH5540), along the line of the postulated road east to Tomen-y-Mur.

References for Pen Llystyn

  • Historical Map and Guide – Roman Britain by the Ordnance Survey (3rd, 4th & 5th eds., 1956, 1994 & 2001);
  • The Roman Imperial Army by Graham Webster (Constable, London, 1979).

Map References for Pen Llystyn

NGRef: SH4844 OSMap: LR123

Roman Roads near Pen Llystyn

Possible road: N (12) to Segontivm Possible road: ESE (14) to Tomen Y Mvr