Castell Caer Seion

Castell Caer Seion

Castell Caer Seion at the summit of Conwy Mountain
Castell Caer Seion shown within Conwy
Alternative name	Castell Caer Lleion, Castell Caer Leion, Conwy Mountain Hillfort, Sinnodune
Coordinates	53°16′57″N 3°51′44″W / 53.282512°N 3.862296°W / 53.282512; -3.862296
OS grid reference	SH 75938 77782
Altitude	244 m (801 ft)
Type	Hillfort
Width	95 m (310 ft)
Volume	30351 m² (326699 f²)
Diameter	326 m (1069 ft)
History
Material	Stone, earth
Founded	6th–4th centuries BC (first phase), 3rd century BC (second phase)
Abandoned	2nd century BC
Periods	Iron Age
Site notes
Excavation dates	1906, 1909, 1951, 1952, 2008
Archaeologists	H. Picton, W. Bezant Lowe, W .E. Griffiths & A. H. A. Hogg, George Smith
Condition	Ruined, but good.
Management	Cadw
Public access	Yes
Designation	Scheduled Ancient Monument

Castell Caer Seion is an Iron Age hillfort situated at the top of Conwy Mountain, in Conwy County, North Wales. It is unusual for the fact that the main fort contains a smaller, more heavily defended fort, complete with its own distinct defences and entrance, with no obvious means of access between the two. The construction date of the original fort is still unknown, but recent excavations have revealed evidence of occupation as early as the 6th century BC, whilst the smaller fort can be dated with reasonable certainty to around the 4th century BC. Whilst the forts were constructed in different periods, archaeologists have uncovered evidence of concurrent occupation, seemingly up until around the 2nd century BC. The larger fort contained around 50 roundhouses during its lifetime, whereas examinations of the smaller fort have turned up no more than six.^[1] The site was traditionally associated with Maelgwyn Gwynedd (c. 480 – c. 547 AD),^[2] but there is no evidence pointing to a 6th-century occupation.^[3] The fort and wider area beyond its boundaries have been said to retain significant archaeological potential, and are protected by law as a scheduled ancient monument.^[2]