The veneration of the Madonna della Guardia in the Cisa Pass has rather recent origins. The church was built at the top of a steep staircase, located just after the Pass, between 1919 and 1922. It was declared a sanctuary in 1930 and ever since, every 29 August, hundreds of faithful pilgrims from Tuscany, Emilia and Liguria have repaired there. 

Sources: Wikipedia