St Mary's Church, Hayscastle, consists of a nave and chancel. The detail of the chancel arch suggest a twelfth century date, which can be assumed also for the adjacent castle mound (NPRN 305307). The church was modernised in 1927. The church was a dependent chapelry of St David's Church, Brawdy (NPRN 419487) until the 17th century.

J.Wiles, RCAHMW, 14 May 2002