O’Cahan’s castle today is a circular grassy clearing within the surrounding forest of the Roe Valley Country Park. The strongly defensive nature of the site can still be understood by the height of the platform above the river and the steeply sloping ground down to it. A three storey tower house above this must have looked very impressive. Limited archaeological investigations were carried out in 2009 after Geophysical anomalies had suggested the survival of portions of the associated bawn and fishpond. Modern fill was found covering much of the area investigated, but the corner of the castle was identified with bedrock shored up to take this, and fragments of glass and pottery. You can read more at: www.excavations.ie/report/2009/Derry/0020515/
