 During the 17th Century, small quarries were opened, with major quarries being developed in the 18th Century to produce the Bath stone used for many of the buildings in Bath and elsewhere in the UK, including Buckingham Palace.Stone was extracted by the "room and pillar" method, by which chambers were mined, leaving pillars of stone to support the roof.These mines were once owned by Postmaster General Ralph Allen (1694-1764).