The Zwingel is a narrow footpath along the Neckar front that leads to the Hölderlinturm. It was originally an open space between the old city wall, on which the houses of the southern Neckargasse and Bursagasse still sit today, and the outer wall, the Zwingermauer. As a forewall, it was a lower outer wall, which was secured by individual round towers (Neckartorturm, Hölderlinturm). The Zwingel was the favorite walkway for the sick Hölderlin.