バート・カールスハーフェン
The name Frederick William Northern Railway is not only applied to the line between Kassel and Bebra, but also to the whole route between Warburg and Gerstungen. The first line built in the Electorate was the "Carl Railway", the line between Kassel and the Weser river port of Carlshafen (now Bad Karlshafen) then considered the most important line to be built in the state. Subsequently, the two links to Warburg and Gerstungen were added to create the Frederick William Northern Railway.