Rocca di Ravaldino, Medieval fortress in Forlì, Italy

Rocca di Ravaldino is a brick fortress in Forlì with a square plan, a low cylindrical tower at each of its four corners and a squat square keep at the centre of one wall. A stone band runs around the towers partway up, and arched corbels support the upper sections. The medieval core was largely rebuilt from 1471 for Pino III Ordelaffi by the architect Giorgio Marchesi Fiorentino.

A document of 1253 in the Libro Biscia records a fortified building at Borgo Bonzanino, whose name evolved into Ravaldino. On 8 August 1332 Bagnacavallo helped fund a fortress here, and Egidio Albornoz strengthened it in the 1360s and 1370s. From 10 June 1471 Pino III Ordelaffi had Giorgio Marchesi Fiorentino rebuild it; Girolamo Riario added the citadel by 1483 and Caterina Sforza a third ravelin in 1496.

The fortress is also called Rocca di Caterina Sforza because it was the main setting of her conflict with Cesare Borgia. In 1496, as regent for her son Ottaviano, she had a new ravelin built and the citadel strengthened, using materials taken from the Palazzo Comunale. The fortress appears in several missions of the video game Assassin's Creed II.

The complex is a working prison, so the interior and the exhibition rooms are not freely open; visits are arranged in advance. From outside, the brick tower, the corner towers and the filled-in moat line can be seen along the perimeter. The site lies near the Ravaldino gate, on the side of Forlì facing the hills.

The keep's only entrance was a spiral staircase running through all three floors; a light shaft beside the entrance hall let air circulate. Its underground storeroom, reached by a small door, led to a second cellar beneath the Palatium. Both are now largely flooded, a problem the chronicler Cobelli already recorded in the fifteenth century.