The building fabric of the current town of Montaione allows us to imagine the shape of the castle. The medieval settlement can be recognized in the layout of the central blocks of the current historical center. These are ordered by three longitudinal road axes and divided into regular segments by the minor, orthogonal roads. In the thus described network, one can recognize the sequences of the regularly-shaped lots destined for various uses of the newly founded village: portions to be used for construction of private houses or public buildings, or spaces to be left free for public use (the piazza). The regular Montaione layout is a confirmation of its origin. Like many second-generation castles, the project referred to is on a rational foundation, with a simple layout, based on the subdivision of a regular geometric space into residential spaces, service roads, and provided with a central public space, a piazza, obtained simply by leaving free a part of the central block. The same type of "urban" layout can be found in the historic center of Gambassi, corresponding to the site of the castrum novum, also the fruit of a founding project carried out in the last quarter of the 12th century. An image of how the castle of Montaione could have looked, as it was also represented by Leonardo in the early 16th century, can be observed in an exceptional drawing of great detail, a 16th-century watercolor, conserved in the Carte Strozziane collection at the State Archives of Florence. The map represents a bird's-eye view of the village of Montaione seen from the west. The five long urban blocks defined by the streets running parallel from the western gate area (Porta Guelfa) to the eastern end of the castle are perfectly recognizable. At this point Porta Fiorentina is drawn almost frontally: it is the best fortified, with merlons and perhaps a vestibule. The wall circuit, on an oval plan, is punctuated by nine wall towers, three on the northern side and five on the southern side. For six of these towers, we know the name by which they were called at the end of the 14th century: Torre dell’Infrantoio, Torre del Merlo, Torre del Lione, Torre di Belvedere, Torre Nuova, and Torre di Parentella. At the center of the blocks, the space saved from the construction of the houses was left for the castle square, equipped with public well, located in front of the façade to the church of San Regolo. The castle must therefore have included the blocks facing the current streets named for Chiarenti, S. Ammirato, and Cresci, excluding the portion of the town around the current Piazza Branchi, an expansion certainly posterior to the 14th century. The Montaione castle in the 16th century watercolor, therefore, corresponds to the dwelling area that Leonardo saw and drew, still defended by its curtain wall, its towers, and its fortified gates.