The site of a post-medieval corn mill with a horizontal water wheel. The Marown parish place-name records (isle-of-man.com/manxnotebook) show the surname McHelly (also recorded as McHelley/McHelly) associated with a treen adjoining Kirk Marown in the 16th-17th centuries: Gilbert and Fynlo McHelly held land in an adjacent treen per the 1643 Manorial Roll, with a Ffynlo McHelly recorded at Camlorge; this is the family name from which the mill's name most likely derives, though no separate manxnotebook entry specifically documenting "McHelly Mill" itself was located.