Route 46, measuring 70 kilometers, stands as Germany's longest officially recognized abandoned motorway. Originally conceived during the Nazi era, construction commenced in 1937 but was halted in 1939 due to the impending Second World War. The motorway was designed to connect Bad Hersfeld and Würzburg, emphasizing scenic views like the Homburg castle ruins. After the war, the project was deemed impractical and was never resumed, leading to the establishment of the A7 as the primary north-south route. Today, Route 46 is a listed monument, recognized since 2003 as the longest preserved section of an incomplete motorway in Europe. It has become integrated into the landscape, providing habitats for various flora and fauna, and is accessible to hikers. Information boards along the route educate visitors about its historical significance, reminding them of the ambitious yet unrealized plans of the past.