From Graces Guide
Trethellan Mine is in the parish of Gwennap, union of Redruth, Cornwall, and within the mining district of Gwennap. It is situated 3 miles from the town of Redruth.
Grace's Guide is the leading source of historical information on industry and manufacturing in Britain. This web publication contains 123,217 pages of information and 190,144 images on early companies, their products and the people who designed and built them.