The fourth stage takes cyclists from Minden via Petershagen, Stolzenau and Landesbergen to the asparagus town of Nienburg. It has a length of just under 60 kilometers.
From Minden, the Weser Cycle Path leads through wide, only slightly hilly countryside to Petershagen. Petershagen Castle is located in the town center. From Petershagen, the Weser Cycle Path leads north via Gernheim and Großenheerse to Buchholz with its old fortified church. You then cycle through Schlüsselburg and Stolzenau, situated directly on the banks of the Weser. Stolzenau's landmark is the twisted spire of St. Jacob's Church. The route continues past the site of the former Benedictine monastery of Schinna, one of the oldest Protestant half-timbered churches in Germany. In Landesbergen, the main route takes you over the Weser bridge into the town center of Landesbergen with the wedding mill. The route continues along the lock canal, past the Landesbergen barrage, to Estorf. Through Leeseringen and the Nienburger Bruch, the route leads directly to the asparagus town of Nienburg. The church tower of St. Martin can be seen from afar.