That one of the myths of WW2. The Germans stopped everything cold at Monte Cassio. After it was destroyed, it fell.
I was thinking more Stalingrad, where the rubble made it easier for the Soviets to defend.
“The capture of Monte Cassino resulted in 55,000 Allied casualties, with German losses estimated at around 20,000 killed and wounded.”
“Fourth and final battle”
https://en.wikipedia.org/wiki/Battle_of_Monte_Cassino