The salient of Soglio l'Aspio (4375 ft.), between the frontier and the Upper Astico, was practically in the air, and could only be considered as an outpost.
But the main line between the Posina and the Astico, which ran by Monte Maggio (5,730ft.), Monte Toraro (6,1.75 ft.), Campomolon (6,030 ft.) and Spitz Tonezza (5,512 ft.), was not satisfactory for defensive purposes.
Behind the line the ground falls away southeastward in a steep glacis that drops abruptly in the end to the Posina on the south and the Astico on the east.
To the west of the Val d'Assa that Cadorna had ordered the preparation of a third line of defence that ran from Cima Portule (7,570 ft.) east of the Val d'Assa and round the southern rim of the Asiago basin by Punta Corbin across the Astico to the mountains south of the Posina.
Corps (the 35th) was in line between the Vallarsa and the Astico, the Roma Bde.
The offensive opened on May 14 with a very heavy bombardment along the whole line from the Val Lagarina to the Val Sugana; but the concentration of fire was most intense between the Vallarsa and the Upper Astico, and against this sector, the following day, the main infantry attack was launched.
Corps had for the most part retired beyond the Posina or down the Astico to the plain, and had been replaced by the 27th Division.
On May 27 Dankl's left wing was down in the Astico valley and close upon Arsiero, and on the following day his centre crossed the Posina in force and attacked the Italian 27th Div.
The line now held by the Italians (27th and 9th Divs.) was the last bulwark defending the plains in this sector, and both here and across the Astico the Austrians made a great effort to break through.
Gonzaga) taking both sides of the Astico valley.
It has been suggested that the Archduke should have pushed straight for the plain, down the Lower Astico valley.
Was reinforced by guns sent up by Enego, and in the Lower Astico, to stop the Archduke Charles.
The line chosen by Krauss ran from south of Rovereto in front of Col Santo to the Borcola Pass; thence along the rim of the Arsiero plateau, north of the Posina and east of the Upper Astico; thence north-eastward across the Val d'Assa to Monte Mosciagh, and thence northward to the old frontier.
Although Alpine troops gained a footing north of the summit they were subsequently blown off by a mine, and Monte Cimone, which rises sheer-sided, like a vast battleship, between the Astico and the Rio Freddo, completely dominating the Arsiero basin, remained in Austrian hands.