This fortress was built around 1000 to control the Ferrarese plain. A gigantic chain of 600 meters connects it to another fortress on the other side of the river, used to block the passage and ask for payment from those who wanted to enter. It is a UNESCO asset.
fluvial defensive structure located in Stellata, a hamlet of Bondeno, in the province of Ferrara. Located on the southern bank of the Po river, it was connected to the Rocca Benedetta di Ficarolo on the other river bank: a chain pulled between the two fortresses acted as a river barrier for defensive reasons or to impose customs duties on merchant ships (via Wikipedia https: / /it.wikipedia.org/wiki/Rocca_di_Stellata) other useful link: ferraraterraeacqua.it/it/bondeno/scopri-il-territorio/arte-e-cultura/castelli-torri-campanili/rocca-possente-di-stellata