The Great Lakes are the world’s largest system of fresh surface water. Its five lakes- Superior, Huron, Michigan, Erie and Ontario-are visible from the moon and hold about 20% of the world’s freshwater supply. They were carved out and filled by prehistoric glaciers, and cover more than 243,000 km. (93,823 sq mi). This is one of the most biologically diverse regions in Canada with more than 150 fish and 50 plant species, some of which are not found anywhere else on earth. First time ever! Your coins are crafted with raised land against a translucent enamel filled lake. These coins feature an interpretation of the bathymetric depths below the lake surface based on data from the Canadian Hydrographic Service. Your coins are proof-finish fine silver (99.99% pure), enameled. Limited to 10,000 coins (each) worldwide.