Day four stays inside the Kaiserstuhl and carries the biggest climbing load of the loop. From Breisach, the route moves straight into vineyard country, using smaller roads that keep switching between valley floor, slopes and viewpoints. The Lenzenberg loop pulls the ride deeper into the Kaiserstuhl before the cycle path between Wasenweiler and Bötzingen gives a short flatter section. After that, the defining climbs arrive: Vogelsangpassstraße, Schelinger Höhe to Bahlingen, and later the bends of Texaspass. Between them, the route shows exactly what shapes this wine region: vine-covered hillsides, open ridges and views across the Rhine plain. After the Neun Linden waypoint, the final kilometres drop into Oberrotweil, a wine village at the foot of the slopes.
