Poggio Imperiale Fortress

How to reach

The fortress of the Poggio Imperiale dominates the town of Poggibonsi and is easily reachable from the center following the indications.


The Medicean Fortress, called 'Poggio Imperiale', built between 1488 and 1511 by the great architect Giuliano da Sangallo, in charge of Lorenzo the Magnificent, at the dominion of the Cassia road toward Siena, was one of the first tests for the realization of the new conceptions of fortification that were developing in those years. Its importance in the history of military architecture is great. No other urban enterprise undertaken in the 15th century in central Italy has the characteristics of majesty of this: on the 'Poggio Imperiale' Lorenzo didn't want to raise only a great fortress; he wanted to start the foundation of a new city. The work was incomplete, either for Lorenzo's death in 1492 or for the evolution of the conflict between Siena and Florence with the consequent end of the strategic importance of the hill, and the fortress has come to our days in its embryonic state. For this reason, it is easier for us to read its structure thanks to the lack of architectural contamination.

The work is formed by two structures tightly tied up among them: the walled enclosure of the hill and the fortress itself. On the western side of the hill lie the incomplete bastioned walls, erected for about half of its programmed extension. These don't follow a particular geometric line but were modeled on the ground orography and developed for around a kilometer.

The years of abandonment and carelessness have created a situation in which today the work is almost totally amalgamated with the surrounding nature, but still in a good state of maintenance, requiring retries of the solidity and of the care set in its construction. The walls were realized primarily in bricks, with the exception of the angles and the gun holes, for which stone was used. The inner space of the walls is endowed with a 'gallery of listening' against the hostile mines. On the most western side, we find the only gate, built entirely in stone and gifted in origin by a drawbridge from which a hall, adorned with two coats of arms in stone of the Florentine Republic, and the aforesaid gallery can be accessed. On the left of the gate rises a stone tower, the only remnant of the preexisting settlement on the hill, enclosed in the new defensive system. This settlement, called 'Poggiobonizio', is returning to the light, thanks to archaeological excavations. Crossing the gate, a road in beaten earth leads to the peak of the relief, where the fortress rises.

The fortress is in a plain place, and thanks to this, it was possible to give a geometric rectangular form to its plan with a point, like a barbican, set to the center of the oriental external side. This particularity let the plant of the construction look like a pentagon. On each of the angles, a bastion is found: two on the western back side toward the city and three (two plus the point) on the opposite side. To one of the two western bastions are connected the hill bastioned walls. Also, access to the fortress is practiced on this side. A long gallery leads us to the inner area through the construction of four plans, called keep but anymore a barracks built on the north-south axle, and long so much to reach the two great sides of the fortress and the gift of a chapel.

The fortifications of the fortress are most curate in comparison to those of the external walls, but they are also built in bricks with gun holes and the angles strengthened in travertine stone. Only the external point was realized entirely in stone for all its height. On all the bastioned walls of Poggio Imperiale are practiced gun holes. Up to a few years ago, the inner ward of the fortress was turned into cultivation; recently, works were begun to recover the space with the restoration of the 'keep'; today, it is often used as the seat of exhibitions. It would be opportune to recover to green the rest of the inside area, from which one can enjoy a magnificent view on the outskirts.

The fortress of 'Poggio Imperiale', for the age in which was built,  can be considered the forerunner of 'bastioned-city' that we will in large part find in the fortified architecture of the following centuries.

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