Once Cortina was taken it was immediately clear that it could not be held securely without also taking the commanding heights above it - the Tofane to the north-west and Pomagagnon and Monte Cristallo to the northeast as well as the northern head of the basin itself - Val Travenanzes, Val Fanes and Val Acqua di Campocroce. Another objective strategic objective to be achieved was the occupation of the Alemagna road between Cortina and . Thus at the end of May 1915 Italian troops advanced the line of investment: Col Drusciè-Cadin-Staolin, a line from which the attack on the Som Pouses defense line would be attempted.: