Sydney Mines is a community and former town in Cape Breton Regional Municipality, Nova Scotia, Canada. Founded in 1784 and incorporated as a town in 1889, Sydney Mines has a rich history in coal production although mining activity has now ceased. Prior to a permanent settlement being established, there was significant activity along the shore. Upo…Sydney Mines is a community and former town in Cape Breton Regional Municipality, Nova Scotia, Canada. Founded in 1784 and incorporated as a town in 1889, Sydney Mines has a rich history in coal production although mining activity has now ceased. Prior to a permanent settlement being established, there was significant activity along the shore. Upon the success of coal mining operations, the Nova Scotia Steel and Coal Company constructed a steel plant in Sydney Mines in 1902. The plant, alongside the steel plant in Sydney owned by the Dominion Iron and Steel Company combined to produce more than 50% of Canada's steel during World War I. The plant was later sold to the British Empire Steel Corporation and ceased operations years later.