Ruan Lanihorne lies within the
Cornwall Area of Outstanding Natural Beauty (AONB). Ruanlanihorne, as the name of the parish is spelled, is entirely rural in character with wooded areas in the river valleys. Apart from the
church town of Ruan Lanihorne, the only other settlements of any size are in the south of the parish:
Treworga and
Ruan High Lanes which is right on the parish's boundary with Veryan. The name Lanihorne is perhaps a modified form of Laryhorn (the Cornish name of this place). The village was, from the mid 12th century onwards, the site of an
adulterine castle of the
Arcedekne family and the main settlement was at Sheepstor (Sheepstall) some distance away towards Tregony (where the Pomeroy family also built a castle). In 1334 John Arcedekne was granted permission for the castle by
Edward III. Before the castle was demolished in the 19th century, it was described as having a 40 ft high keep, seven or eight towers and possibly an outer court. ==Demographics==