Estimated Grid Ref. United Mines, along with Ale and Cakes Mine and Wheal Cupboard, were merged around 1780. Later, Poldory, along with the expanded United Mines, joined the Great Consolidated Mines in 1861. This amalgamation was then renamed Clifford Amalgamated Mines, which ceased operations in 1870. Moving into the 1900s, Poldory became a part of Mount Wellington Mine, which operated from 1923 to 1941 and later resumed operations between 1976 and 1991.