The Pentre-felin outlet sluice controls water levels in the Llangollen Canal and enables sections of the canal to be drained. It is one of eight along the line of the canal.

At Pentre-felin, canal water runs into a recess and up to a sluice gate situated under the towing path. The sluice gate is operated by the mechanism on the towing path, and when opened water flows through through a pipe underneath the path to an exit point half way up the sluice wall. From this point water drains away to the River Dee.

This sluice is an example of ongoing renewal, with the sluice wall, set between the original curved ashlar wing walls, rebuilt in engineering brick around 1900.

Louise Barker, RCAHMW, 13 December 2007