Townline Tunnel
The Townline Tunnel is an underwater tunnel in Welland, Ontario, Canada carrying Highway 58A as well as the Canadian Pacific Railway under the Welland Canal.
Tunnel data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).
Other tunnels in Canada
Delaware Aqueduct United States · 137 km Päijänne Water Tunnel Finland · 120 km Orange–Fish River Tunnel South Africa · 82.8 km Ishikawa Tunnel Japan · 78.5 km Brenner Base Tunnel Austria · 64 km Mont d'Ambin base tunnel France · 57.5 km Gotthard Base Tunnel Switzerland · 57.09 km Hong Kong–Zhuhai–Macau Bridge China · 55 km