The WWI front passed directly through the Dolomites, with Italian and Austrian forces fighting at altitude for three years across terrain that was already extreme before you added combat. The physical evidence remains: tunnels, trenches, bunkers, and galleries are preserved at several accessible sites, and hiking through these spaces — where soldiers lived, worked, and died a century ago — is one of the most affecting experiences the Dolomites offer.
The most accessible sites are around Cortina and the Cinque Torri, where the Italian front line is preserved as an open-air museum with restored trenches and explanatory panels. The Lagazuoi — the massive rock wall above Falzarego pass — can be climbed via a former Italian military tunnel cut through the mountain from bottom to top; the walk up takes about two hours through the rock, emerging at the summit with views in every direction. At the top, the Rifugio Lagazuoi is built into the old Austrian position. Cable cars down avoid the need for the same route twice. The Great War Museum at Pieve di Cadore provides historical context.