Castel Castagna is located in the Siciliana Valley overlooking the wonderful scenario of the Gran Sasso mountain range, 2,914 metres above sea level. This valley, nestled between the mountains, is so named because Italic people Siculi dominated, until 290 BC, the entire Pretuzio corresponding to the present province of Teramo, when was occupied by the legions of the Roman consul Mario Curio Dentato.
The first recorded mention of Castel Castagna came in twelfth century when the Catalogus Baronumtestifies the existence of Castel Castagna in 1150-1168. On this book Castellum Castonee was feudal estate of Trasmondo and his brother Berardo. Charles I king of Sicily, known also as Charles of Anjou, assigns Castanea to giustizierato di Abruzzo Ultra in 1273.
The church of St. Petri ad Castaniam in Valle Ciliani paied the tithe of the Papal Curia in 1324.
The marriage of Margherita, Countess of Manoppello, and Napoleone Orsini in 1353, cames the SicilianaValley under the direct influence of the powerful Roman Orsini family. Castel Castagna, was enfeoffed in the marquisate of Alarcón Mendoza in 1526.
In 1669, Castel Castagna came under the influence of Acquaviva Duke of Atri and was taxed, as its owner, in place of Marchese della Valle Fernando de Alarcon y Mendoza.
In 1683, a period in which the Abruzzo was devastated by the phenomenon of brigandage, Castel Castagna was sacked by Santuccio's bands, a dangerous robber, whose headquarters was located in Torricella Sicura.
In the french period, with law dated 2 August 1806, the feudal system was abolished and the following year Castel Castagna was still looted by a group of insurgents against the Napoleonic regime, stationed in Farindola's mountains.
After the Italian unification, by Royal Decree June 28, 1863, Castel Castagna took its present name.
The old town centre has preserved buildings with stone portals dating from the fourteenth to the eighteenth centuries. Of fine workmanship are the church of San Pietro Martire and the Abbey of Santa Maria di Ronzano.
Not far from the center of town, near the river Mavone, stands the church of Santa Maria di Ronzano that he probably part of an important Benedictine monastery. Santa Maria di Ronzano represents one of the most important monuments of the region and demonstrates the transition between Gothic and Romanesque style.
The church was built by the last two decades of the twelfth century, as attested by the apse frescoes dated 1181 and the fire of 1183 that has left visible traces inside.
The paintings style inspired by early Christian art and makes them unique because they do not suffer from the Byzantine influence that was exercised in most of Abruzzo Romanesque works. On the right you can admire the stories of the Old and New Testament, on the left stand the Patriarchs and in the apse a blessing Christ. Great beauty of the figures of the Annunciation of the Virgin shows examples of Gothic in Northern Europe. Particularly significant is the "Flight into Egypt" with stylistic similarities found in the works of eastern France. The vortices drawn on the figures refer to the gable of the cathedral of Autun in Borgogna. The architectural prototype of Santa Maria di Ronzano has very precise feedback with the European architecture of the twelfth century and particularly Pugliese.
The basilica has three naves, covered roof and divided by arches on square pillars with pilasters leaning. Belongs to the church of Santa Maria Ronzano a cross reliquary containing a fragment of the True Cross of Christ found by Elena Augusta, mother of Roman emperor Constantino. It is an ancient reliquary that holds a double cross. The verse is decorated with gems, arranged on a background of gold filigree.
Appears on the side an inscription in Gothic letters that refer to "the Blessed Cosma, San Giacomo Apostolo, the Christ’s Wood, the cloth with which Christ was presented in the Temple, San Tommaso Apostolo," relics that may have been placed inside the small glass case placed over the Cross.
This relic is rare, because few are stauroteche double wishbones still exist.
The reliquary ranks Castel Castagna among the most important centers of medieval Christianity. In fact, as is written in the Chronicon Paschale, the true cross of Christ was discovered in 320 AD by Elena Augusta, mother of Emperor Constantine, who erected on the highest hill of Golgotha, a monumental cross in gold foil decorated with gems.
The presence of the Benedictine abbey and the relic of the Cross of Christ testify the close relationship between Castel Castagna, the Valle Siciliana and medieval christianity.