The fortified site of Castel di Mura or Castrum de Muris is situated on the summit of Monte Castello (827 m a.s.l.), in the Apennines near Pistoia, close to the Apennine ridge. It lies a short distance from the village of Lizzano (San Marcello Piteglio), where a _curtis_ is documented in the 10th century, and the earlier parish church of the Montagna di Pistoia was also situated. Castel di Mura was part of the Apennine ridge defensive system, linked to routes leading to Florence, Pistoia, Lucca, Modena and Bologna, formed by the ‘Torri di Popiglio’ (Fortezza della Sicurana), the ‘Torre del Partitoio’ and other fortified sites, reorganised by the Municipality of Pistoia in the 1330s. Moreover, at least between 1358 and 1361, it was the seat of the ‘Captain of the Mountain’. Prior to these excavations (begun in 2017), the site was known through field surveys, archive research and reports of finds. The excavations have concentrated on a number of areas on the summit of Monte Castello, where both field survey and georadar survey have revealed the presence of structures. The first campaign (2017) analysed the phases of abandonment and agricultural use in more recent centuries and the residential and military phases of the 14th and 15th centuries. The base of a tower was exposed, with a room abutting it externally, which links it to a polygonal enclosure that had a turret and cistern. A probable gate was also identified; open in the south-eastern section of an external curtain wall, identified in several places, along the summit’s profile. The gate was situated in correspondence with the steepest part of Monte Castello, an impracticable zone, probably altered by landslides that could have caused the partial destruction of the gate of which only one jamb and part of the threshold were preserved. Oral sources recall the existence of an entrance in this position. The memories are linked to the celebration of a procession on the occasion of the feast of the Assumption, which reached the summit of Monte Castello at the south-eastern edge. The excavations excluded the existence of a second gate, also recalled by oral sources, at the north-eastern corner where the present access point to the summit is situated.

In 2018, the excavations identified a new forepart attached to the polygonal enclosure in the north part of the site, and excavation of the gate in the outer curtain wall, at the south-eastern edge of the area, continued. The resulting evidence suggests the possible existence of a flight of steps that would have overcome the difference in height between the summit plateau and the base of the entrance. In the area outside the tower, in correspondence with the south side, several charcoally layers were excavated, probably the result of the burning of timber elements, connected to the tower walls, evidence of which was seen in the previous campaign. The remains of the fire overlay an abandonment layer, datable to the 14th-15th century, which had obliterated an area paved with sandstone slabs, bonded with mortar, and cobblestones. The identification of a posthole in this paved area suggests the presence of timber structures abutting the side of the tower. Lastly, the cistern area was excavated, where together with recent activity, perhaps agricultural, wartime explosive devices were found, which indicate that the castle was reused as a deposit by the partisans. The investigations completed thus far have identified structures mainly attributable to the refortification begun in the 1350s. This was promoted by the municipality of Pistoia that had made provision for the construction of a _ fortilitia_ _sive_ _roccha_ _in_ _Castrum_ _de_ _Muris_, also restructuring some of the buildings already present in the _castrum_, such as the tower, the external curtain wall, the cistern, and several _domus_. Information obtained from oral sources confirms the memory of the existence of an entrance on the south-eastern part of the plateau, where the gate in the external curtain wall was identified. There was also recollection of a pathway, no longer visible, which linked Monte Castello to the nearby village of Lizzano. In use during the last century, it functioned almost exclusively as the processional route on the occasion of the feast of the Assumption.

Nel 2019 è stato completato lo scavo della cisterna (saggio 2/c.f. 3), interrotto nel 2018 per il rinvenimento di ordigni bellici; è proseguita l’indagine nel saggio 4 ed è stato aperto il nuovo saggio 7 lungo la cinta muraria del castello. Al di sotto degli strati interessati direttamente dall’allestimento e dall’occultamento di un deposito partigiano di armi della Seconda Guerra Mondiale, il completamento dello scavo della cisterna ha evidenziato un unico strato di riempimento (US 3067), disturbato anch’esso dagli usi bellici. Lo strato era costituito da argilla e humus, pietrisco e pietre anche lavorate, frammenti ceramici, elementi metallici e proiettili. Rimosso il riempimento, la cisterna è apparsa costituita da un unico vano a pianta rettangolare (circa 5,35 x 3,30 m) con copertura a botte (altezza massima 4,50 m). La cisterna era alimentata da acque meteoriche; nella precedente campagna erano già state individuate due bocchette di adduzione, aperte nella volta per immettere l’acqua, convogliata attraverso tubature in cotto, delle quali sono stati recuperati numerosi frammenti. Nei lati lunghi, in prossimità dell’imposta della volta, sono state rilevate cinque buche per lato per l’alloggiamento della centina. Il fondo del bacino è concavo, con al centro una depressione sub-circolare funzionale alla raccolta dei depositi della decantazione dell’acqua. La struttura è stata in parte scavata nel suolo arenaceo e in parte costruita con bozze di arenaria (visibili nelle lunette dei muri di testa) e con lastre legate con malta tenace e biancastra. All’interno, il fondo e le pareti, fino alla linea d’imposta della volta, sono coperti di intonaco rosato. All’esterno, la volta era stata livellata con una gettata di cementizio con inclusi calcarei e arenacei e con sfaldature di arenaria. Nella volta si apriva una botola probabilmente rettangolare della quale si conserva un solo lato originario. Le indagini nel saggio 4 hanno portato all’individuazione, nelle aree sud ed est, esterne alla torre (c.f. 1) di un piano pavimentale (US 115 ) sul quale sembrerebbe crollata la parete meridionale della torre stessa (USM 29). L’apertura del saggio 7 ha permesso di evidenziare una torretta avanzata (c.f. 4/amb. 1) a pianta poligonale, con parte di una probabile feritoia a ‘buco di serratura rovesciato’. I risultati delle indagini 2019 hanno portato a più puntuali definizioni topografiche e cronologiche del sito. I tratti occidentale e settentrionale della cinta muraria (c.f. 4) erano stati probabilmente allestiti a partire dalla base di una sorta di fossato o spianata esterna e presentavano un numero, ancora da precisare, di torrette avanzate. Infine, l’individuazione del piano pavimentale sul quale è crollata la parete meridionale della torre, permetterebbe, anche se in modo ancora preliminare, di collocarne l’abbattimento in un momento anteriore alla metà del XV secolo.