Castello di Gressa, Medieval castle in Bibbiena, Italy.

Castello di Gressa is a fortress from the 10th century with two distinct wall systems: an outer wall with an irregular polygonal shape and an inner octagonal wall standing about 16 feet (5 meters) high. Sandstone and limestone walls enclose residential buildings, a church, and two water cisterns that served the residents' daily needs.

Bishop Elemperto ordered the castle's construction between the 10th and early 11th centuries while leading the Arezzo diocese from 986 to 1010. Its founding reflects a period when the church used fortified settlements to strengthen its control over the surrounding countryside.

The name Gressa appears in a May 1078 deed signed under the portico of San Pietro inside the castle, when Sibilla and her grandsons transferred their feudal rights to the prior of Camaldoli. The church of San Jacopo still stands between the two wall circuits, beside the old bishop's residence.

The castle sits along the road connecting Bibbiena to the sanctuary at La Verna, with directional signs starting from the Tripoli district to guide your way. Wear sturdy footwear since the approach involves walking through hilly terrain, and prepare for a moderately paced hike through the countryside.

Pier Saccone Tarlati, lord of Arezzo, returned Gressa reluctantly and kept the exact height of its walls in mind. On his deathbed he gave the measurement to his son Marco and ordered a night escalade; the assault failed because the castle was well defended, and Pier Saccone died on hearing the news.