Italy declared war against Austria-Hungary on 23 May 1915, even if the date generally remembered is 24 May 1915, when both armies entered in action, i.e. 99 years ago today. There were fights on the northern and Eastern fronts, but on the Italian coasts too. The most famous is th bombardment of Ancona (23-24 May 1915), in the Marche region, which was the first naval engagement of the Adriatic Campaign between the navies of Italy and Austria-Hungary. The destroyer SMS Dinara and torpedo boat Tb 53T bombarded the port of Ancona, whereas the destroyer SMS Lika, on a reconnaissance mission between Palagruža and Cape Gargano, shelled the semaphore and radio station at Vieste.
There were other fights on 23 May and 24 May 1915. As an illustration, I’ve chosen an Italian postcard which shows us the light cruiser SMS Novara, a destroyer and two torpedo boats entering Corsini Channel and shelling an Italian torpedo boat station, another semaphore station, and few batteries of coastal artillery (source: wikipedia).