In WW1 there was a fort (Fort Herman) which has been built by the Monarchy to withstand both conventional artillery (mainly small calibre close range shooting) and bombs from airplanes. And it was situated between two hills so it was almost impossible to go close enough to shoot. And they controlled the valley (next to Bovec).
The Italians figured that they _really_ needed that valley route. So they pulled up artillery 2 hills before (it was some 6-8 kilometers away!) and started shooting in the general direction of the fort. In the beginning they needed a lot of adjustments, but after a few months(!) of shooting they pretty much calibrated the thing. So they kept shooting. For months. To no end. I think it took about a year when the fort was so much damaged that the last soldier left it, and the Italians marched forward (and cleaned up a lot of Hungarian and Austrian soldiers in due course, and I do not mean water and soap).
They were surely pretty fucking frightening there.

(Wrote from memory, so it may contain traces of historical inaccuaries.)