This is the view of the Quadrilateral from the Austrian perspective. You are looking straight across the Po Valley to the northern Appenine range on the horizon (Appennino settentrionale). Mantova is in the valley left of center with Castiglione south of the lake.
Austria created a fortress system south of the lake, the Quadrilateral, comprising Verona, Peschiera, Legnago and Mantova. The Imperial advisors in Vienna were too willing to commit resources to defend the key fortress. The Austrian HQ Staff faced the extra challenge of how to exit from the mountains without being held-up at one of the three main approaches (SS-45bis, SS-12, S-46). This usually required sending random parts of the army down different passes, to confuse the enemy as to their main thrust. That crazy-shaped Lago di Garda is the symbol of the whole campaign. The armies danced around it, most of the battles occurred within 10 or 20 miles of it. Rather than helping the Emperor, the fortress of Mantova became an obsession that just further drained Franz’s troops and treasure.