Saint Lawrence River HVDC Powerline Crossing

The Saint Lawrence River HVDC Powerline Crossing is the crossing of Hydro-Québec's Quebec-New England HVDC transmission line under the Saint Lawrence River between Grondines and Lotbinière, Quebec, Canada. The crossing is remarkable for being first implemented as an overhead crossing and later replaced by a cable tunnel.

Source: Wikipedia — Saint Lawrence River HVDC Powerline Crossing (CC BY-SA 4.0)