The Round Church of the Knights Templar (London) was completed in 1185. Its Great West Doorway, constructed of caen stone, has survived in almost original form. Macfadyen describes the conservation work carried out on the Doorway in 1984. The treatment included removal of a calcium sulfate skin by air abrasive methods, repointing of open joints, and grouting of voids with a liquid grout. The conservation work led to the discovery that during a restoration in the 1840's the inner arch of the Doorway had been rebuilt.