Highway 104 in Nova Scotia, Canada, runs from Fort Lawrence at the New Brunswick border near Amherst to River Tillard near St. Peter's. Except for the portion on Cape Breton Island between Port Hawkesbury and St. Peter's, it forms the main route of the Trans-Canada Highway across the province.

Amherst is a town in northwestern Nova Scotia, Canada, located at the northeast end of the Cumberland Basin, an arm of the Bay of Fundy, and 22 km (14 mi) south of the Northumberland Strait. The town sits on a height of land at the eastern boundary of the Isthmus of Chignecto and Tantramar Marshes, 3 km (1.9 mi) east of the interprovincial border with New Brunswick and 65 km (40 mi) southeast of the city of Moncton. It is 60 km (37 mi) southwest of the New Brunswick abutment of the Confederation Bridge to Prince Edward Island at Cape Jourimain.