In the summer months of 1922, 1923 and 1924 the ruins of the monastery of Saint Mochaoi of Nendrum was excavated and "restored" by H C Lawlor MA.
Nendrum Monastic Site comprises the remains of three concentric cashel walls on a small hill on Mahee (old name Nendrum) Island.
The inner enclosure contains the Church, the stump of a round tower and graves. There are many walls of various buildings also between the first and second cashels.
On the shore close to the NE side of the site a substantial stone wall runs parallel to the shoreline for about 120 metres at a distance of about 20 metres out from the high tide line (top left of picture below). Lawlor had suggested that this was a fish pond, but it now transpires that it is a mill pond.
Investigation of the so called fish pond in the summer of 1999 led to the discovery of a stone built tide mill and evidence of its earlier evolution.