Exeter Volcanic stone has been widely used in houses, churches, and other historic buildings in a large area of the southwest, east of Dartmoor, including Crediton, through to Cullompton and up to Wellington. This includes, Exeter’s Roman wall, parts of Exeter Cathedral, and the walls of Crediton Church. Any wall containing this stone should be mended using the same type of stone, not just for appearance and authenticity, but because inappropriate materials can react badly with the remaining stone and harm these structures.