Cornwall Archaeological Unit (CAU) undertook an intermittent watching brief based on photographic recording during repairs to a short length of walling forming part of the former Hayle Foundry Hammer Mill complex, this now making up part of the eastern boundary wall of the amenity area called Hayle Millpond Gardens. The site is part of a Scheduled Monument (National No 1204628), and the watching brief was a condition of the Scheduled Monument Consent for the works to remediate wall destabilisation caused by intrusive Buddleia growth. The repairs were undertaken in early January 2019 by CORMAC Ltd, and the final works were completed in July. No new archaeological findings resulted from the work.