Info from Wikipedia
St Cosmas and St Damian Church is an Anglican church in the village of Keymer, in the Mid Sussex district of West Sussex, England. Rebuilt in 1866 in a style similar to the Saxon building it replaced, it is the parish church of Keymer and now lies within a combined parish serving three villages in Mid Sussex. The church bears a very rare dedication to the twin Saints Cosmas and Damian, Christian martyrs of the 4th century.