Right next to the Pile Gate (Vrata od Pila), the Western entrance to the Old Town of Dubrovnik, is possible to spot the Fort Bokar.

This very beautiful fortress used as key point for the defense of the city, built from 1461 to 1463 during the reconstruction of the city walls, “stands in front of the medieval wall face protruding into space almost with its whole cylindrical volume.” (source)
The sea and the sky, creating a strong contrast of colours, enhance its beauty and somehow smooth its rough look.