Piazza Vecchia surrounded the baronial palace on three sides.
In 1740, the Prince of Palagonia built his granary there, capable of storing 1,000 salme of wheat, leaning against a secondary façade of the palace, blocking two windows and occupying part of the square toward the north. The rear area, once the site of underground grain pits and a kiln contemporary with the palace, ended westward in a slope descending toward the current Via Nunzio Nasi, then a natural drainage ditch for rainwater.
The later opening of the street, with the retaining wall, created a confined space—closed to the east by the granary and the palace and to the west by the bastion—accessible almost level from Piazza Vecchia. To the south, a building constructed after the 1940s, converted after the war into a Health Observatory for childhood diseases and demolished between 2007–2008, defined the square’s current layout.
In the 1970s and 1980s, on Holy Thursday, the square was decorated with trees and scenery to recreate the Garden of Gethsemane, serving as the stage for the Capture of Christ in the Holy Week performances.
The construction of the Archaeological and Peasant Civilization Museum, whose administrative process began in 1989 and concluded with its inauguration in 2013, gave Piazza Castello a renewed central role, enriched with historical and cultural artifacts.
Today, the square features the Lucchese Baronial Palace (1605), the Prince of Palagonia’s granary (1740), the Museum, the stone monument from Sabucina’s Statio Petiliana, a Roman milestone, and the short Vicolo Castello, where a carved stone corner projection survives—perhaps a remnant of the Ortolano barons’ building or the Statio Petiliana itself.