Royal Commission aerial reconnaissance on 10th July 2018, during the 2018 drought, identified parchmarks of linear ditches in dry pasture running in a general north-south direction, on the west side of Caerberllan farm (image refs: AP_2018_4245-46 & 4251-52). The ditches are still visible as earthworks on 2023 Welsh Government LiDAR data. The ditches emerge from the steep valley on the south side as curving, parallel ditches resembling a leat or water channel. Beyond Caerberllan, the merge into a single ditch; in total the earthworks run for approx. 320m.

While the remains could be interpreted as a dyke or boundary, it seems more likely that they are a large leat system drawing water from the river uphill. It may be related to medieval activity associated with nearby Castell y Bere

T. Driver, RCAHMW, Feb 2024