 Osoppo hosts a large fortress (La Fortezza o Rocca di Osoppo), now an historical attraction.It played a large role in the defense of Venice against the Austrians in the late 1850s during the time of the Italian Unification of Italy.It was shortly after one of the main battles at this fortress that Leonardo Andervolti composed his treatise, "Meritorious Champions of Italian Independence", a eulogy to a mythical figure, Enrico Ulissi.