The "Rocca Brancaleone" (Brancaleone Fortress) was built in 1457 by the Venetian Republic. Originally, was part of the city walls; today is a public garden. It's comprised of two main parts: the castle itself and the citadel, spread over a total area of 14.000sqm.

translated from: http://it.wikipedia.org/wiki/Ravenna (as of May, 18th,2009)