Originally named Holborn Hill, Millom grew from a small fishing village into a town as a result of the steel industry and the haematite iron ore mining at nearby Hodbarrow, now an R.S.P.B. nature reserve.
More than 300 miners worked the rich deposits discovered in 1868, and mining continued until the 1960's. As the sea encroached on the mines, it was necessary to build a breakwater to protect the workings. Built of sandstone blocks covered with tar (replaced by concrete, clay, and stone in 1900), the seawall was up to 50 feet high in some places. Little remains of the former industry, and the area is now a holiday village offering water sports.