Castell Gronw Castle Mound

Cadw's description

Summary description and reason for designation

The following provides a general description of the Scheduled Monument.

The monument comprises the remains of a motte, an earthwork castle mound, dating to the medieval period (c.1066-1540 AD). A motte is a large conical or pyramidal mound of soil and/or stone, usually surrounded by either a wet or dry ditch, and surmounted by a tower constructed of timber or stone.

The motte is situated in the private garden of Pen y Bont cottage. It is 23m in diameter at the base, between 4 and 4.5m high, and 10m diameter across the top. The north and east sides of the mound are terminated by retaining walls over 1m high, which mark the boundary of the cottage on the east and the pavement on the north. The north side of the motte has been planted with flowering shrubs and other garden plants; the remaining sides are mainly grass covered, although the remains of a flower bed are visible on the south side. A concrete pad 2.5m by 2m has been laid on the top of the mound. The septic tanks which serve the cottage lie 8m to the south of the base of the motte.

A wooded area west of the motte is thought to be the site of the bailey, a defended enclosure surrounding, or adjacent to the motte, usually the site of service buildings and stables. This area is bounded by a stream lying in a gully 2m deep on the west and south sides. The remains of a slight scarp or ditch are visible running in a south westerly direction from the motte, but it turns south before reaching the gully. There are no remains to suggest how the south side of the gully would have been connected to the motte.

The castle was located to control movement along the Dee Valley and in particular the crossing of the river at the north-east end of Llyn Tegid. The significant views from the monument are therefore to the north-west along and across the Dee Valley in an arc from south-west to north-east

The monument is of national importance for its potential to enhance our knowledge of medieval settlement and defence. It retains significant archaeological potential, with a strong probability of the presence of associated archaeological features and deposits. The structures themselves may be expected to contain archaeological information concerning chronology and building techniques.

The scheduled area comprises the remains described and areas around them within which related evidence may be expected to survive.