Old St Runius (Old Marown Church), dedicated to Ma Rooney/St Runius, was built around 1200 and served as Marown's parish church until 1853. It was extended westward in 1750-55 using moulded stonework reused from the ruined St Trinian's Church in the same parish, and its original south doorway and windowless north wall survive from the 12th-century build. After serving as a mortuary chapel it fell into disrepair, but volunteers restored it and it reopened for occasional services on 9 August 1959.