Hidden in the Vittoriano monument - on the side nearer to the
Forum (with its entrance on the Via dei Fori Imperiali) - you'll
find a small museum that honours the country's armed forces....
the 'Museo Sacrario delle Bandiere delle Forze Armate'.
The exhibits there include this tiny Motor Torpedo Boat, from World War One:
"Italian MAS boats were comparatively small, at 20-30 tons displacement.
MAS 15 was the only Motor Torpedo boat in history to sink a battleship,
the Austrian vessel Szent István in 1918"... from Wikipedia.