Canso Causeway, Causeway in Port Hastings, Nova Scotia, Canada

The Canso Causeway is a rock-fill embankment crossing the Strait of Canso between Cape Breton Island and mainland Nova Scotia. This structure carries both a railway line and a two-lane roadway linking the island to the rest of the province.

Work started in 1952 and required more than 10 million tons of rock to build the embankment. The official opening took place on 13 August 1955, ending the ferry service that had previously connected the island to the mainland.

The name Canso is believed to come from the Mi'kmaq word kamsok, meaning "opposite the lofty cliffs." The official opening on 13 August 1955 featured a parade of about one hundred bagpipers crossing the causeway, celebrating the new link between Cape Breton and the mainland.

Vehicles use Highway 104 on the mainland and switch to Highway 105 on Cape Breton Island, while trains share the same route. The crossing is continuous without stops, except when the swing bridge opens for marine traffic.

The causeway's rock fill rests on seabed up to 65 m deep, and the Canso Canal at its eastern end keeps Cape Breton Island circumnavigable. The 94 m Canso Canal Bridge is a swing bridge carrying both the road and the railway line across the canal.