The castle of the Counts Guidi rises on top of the town called Strada in Casentino, the chief town of the municipality of Castel San Niccolò. Besides being one of the most important and well preserved fortresses in the Casentino, it is also the building from which the first built-up area originated in the territory.

One can get to the castle by climbing a flight of stairs that lead to the main door. By crossing it, one arrives in Piazza d'Armi from where the structures that compose the stronghold can be distinguished, among them the four parts of the palace. Some of them can be visited: the rooms of the Keep and the right wing of the floor above where a precious fresco depicting the "Annunciazione" with ties to the XV-century Florentine school, is still visible.
The Castle of the Guidi was initially known as "Corte di Vado" and its original structure dates to the XI century, at least, when it already appeared as one of the most inexpugnable bastions owned by the Guidi of Battifolle, some powerful feudatories of the Casentino. From the XIII century on, it became the fixed residence of he family that dominated the area upright until 1349, when a rebellion of the population against Galeotto Guidi ceded the castle and its village to the podestà of the Florentine Republic.
Once it became the chief town of the Montagna Fiorentina town hall, the troops of Niccolò Piccinino tested the castle to the limit. The Visconti of Milan, first, paid this skilful leader who besieged the castle in 1440 and, later, also the last members of the counts Guidi, who had taken refuge in Poppi, did the same. As regards this last war, chronicles have cast light on the atrocities perpetrated by the representatives of this decaying dynasty. In effect, it seems that the Guidi catapulted the prisoners inside the walls to take their revenge for the castellans' relentless resistance. Moreover, once the fortress had been conquered, the Guidi condemned its most irreducible defenders to be hanged along its walls.
After these episodes, the Florentine Republic took possession of the castle again and decided to dismantle the castle's defensive structure and enhance its role as the podestà's residence. Its structure, therefore, went through numerous changes in the lapse of time going from the XV to the XVIII century. Only in 1970, it was decided to perform its restructuring and restorations that could recover the castle's architectural appearance which made it famous and admired in the Middle Ages.