- The Porta degli Angeli was an original Northern entrance to the Addizione Erculea.
- It is built at the start of the region built as the Addizione Erculea.
- The palace with its protruding marble portal and balcony, with a corner balcony, was designed and built in 1493-1498 by Biagio Rossetti as part of the Addizione Erculea.
- The resulting " Addizione Erculea " is one of the most important and beautiful examples of renaissance city planning and contributed to the selection of Ferrara as a World Heritage Site by UNESCO.
- As was usual for the eremitic, cloistered institutions, it was erected outside the city walls, but with construction of new walls, with the Addizione Erculea, it was enclosed in the city.
- Among them are those in the north quarter ( especially the four at the intersection of its two main streets ), which was added by Ercole I in 1492 1505, from the plans of Biagio Rossetti, and hence called the " Addizione Erculea ".
- A new part of the city, named Addizione Erculea ( " Erculean Addition " ) had been built in the previous century : it is commonly considered one of the major examples of urban planning in the Renaissance, the biggest and most architecturally advanced town expansion project in Europe at the time.