In connection with a proposed wind turbine on land at Rhosbeirio, Anglesey Wessex Archaeology undertook a small evaluation with trenches targeted on potential features identified through geophysical survey. Though prehistoric and Romano-British activity is known from the wider area the only features identified during this investigation were former field boundaries thought to relate to post-medieval (1500-1800) or 19th century enclosure.

In November 2014 Wessex Archaeology undertook a watching brief during the installation of a temporary anemometer mast at Rhyd y Groes windfarm on Anglesey. Archaeological monitoring of these works was required as to the east of the site lies the Werthyr earthworks, a large enclosure thought to be in use from the Late Iron Age into the Romano-British period (100 BC- 410 AD).