Situated in and built across the southern end of the west ditch defining Nevern Castle is a small post-medieval building. The building, most likely a cottage, comprises 3 units, a central single storey main unit measuring 6.7m (E-W) by 4.3m (N-S) internally, with a central entrance and 2 windows in the south elevation, evidence of a fireplace in the west gable, a rear entrance in the north elevation and evidence of an internal partition dividing the eastern half of the interior. The walls of this structure stand to roof height, but no evidence for the roof survives. Attached to the eastern corner of the south elevation is a small store 1.9m by 1.4m and to the rear of the property is an annexe 5.8m by 1.9m. The annexe is defined by lower walls and contains an entrance and window in its north elevation. 8m to the north of the building there is evidence of quarrying in the east face of the castle ditch, possibly a source of stone for the building.

The building is depicted on the 1st edition Ordnance Survey of 1889 where it is named Pwll-y-broga (Frog Pond/Pool), possibly a reference to the pond also depicted on the map situated in the castle ditch 30m to the north of the building.

The building was surveyed as part of survey of Nevern Castle undertaken by RCAHMW in 2011.

Louise Barker, RCAHMW, November 2015.