The present building is cruciform Gothic, with a belfry at the crossing, stained glass and a distinctive timbered roof. Christian worship here is traditionally traced to around AD 510, and the church is associated with St Kessog. Look for the unusual 11th-century Anglo-Scandinavian hogback stone, whose curved ridge is carved like a row of roof shingles, along with early-Christian cross-slabs and later grave monuments. If the church is open, the hammer-beam roof, medieval font, recumbent bishop effigy and Colquhoun memorial details add a lot more interest.