A short detour across the Möhne bridge allows you to visit the Himmelpforten monastery ruins. The monastery, founded by Cistercian nuns in 1246, was swept away by a mighty flood when, on May 17, 1943, the dam wall of the Möhne Dam was destroyed as a result of a bombing raid. At that time, 140 years had already passed since the nuns had left their convent. Today, a memorial on the site of the former convent commemorates the catastrophe.