This is the Sacrario militare di Redipuglia, a war memorial built under Mussolini. It houses the remains of 100,187 Italian soldiers killed between 1915 and 1917 in the eleven battles fought on the Karst and Isonzo front.
When you’re there, it’s big, but it is just a gentle slope. A strange effect. Maybe it’s because from the highway I had never more time than for a fleeting glance?