Ermatinger Clergue National Historic Site in Sault Ste. Marie, Ontario, preserves an unusually early built landscape on the St. Marys River through the Ermatinger Old Stone House, the Clergue Blockhouse, and the Heritage Discovery Centre. The stone house, built between 1814 and 1823 for fur trader Charles Oakes Ermatinger, is one of Northern Ontario’s oldest surviving homes and later served many community uses before its restoration as a museum. The blockhouse began as a North West Company powder magazine and was later adapted as living quarters by F. H. Clergue. Together, these buildings connect the region’s fur trade past with its later industrial history.