The fortifications at Castelmur may be, after the Three Castles of Bellinzona, the most important example of medieval valley fortifications in modern Switzerland.
The castle site has been occupied and fortified since at least the Roman era. The important trade road over the Septimer Pass runs through the Val Bregaglia. The Romans built a guard station and village named 'Murus' according to the 3rd century Itinerarium Antonini. The foundations of several buildings as well as one building's hypocaust and two small votive altars have been excavated from the Roman settlement.
After the fall of the Western Roman Empire the Castelmur next appears in 842 as castellum ad Bergalliam. At that time it was owned by the Emperor and held by Constantius of Sargans. In 960 Emperor Otto I granted the castle and right to collect tolls to the Bishop of Chur to help secure this important alpine trade route. In 988 Emperor Otto IIIconfirmed his grandfather's grant to the Bishop and specifically mentioned both the castle and the nearby Nossa Donna Church. The current tower was probably built around 1200.
Over the following centuries the Bishop of Chur and the town of Chiavenna quarreled over Castelmur and in 1121 or 1122 the town captured the castle. However, Pope Callixtus II intervened and forced Chiavenna to return the castle to Chur. In 1190 the Bishop granted the castle to Albertus de Castello Muro or Castelmur. His descendants ruled over the castle until 1264 when Albertus Popus Castelmur stole cattle from the nobles of Chiavenna and Piuro, led to an invasion and the castle being conquered in 1268. These nobles held the Castelmur for four years before returning it to the Castelmurs in 1272. Around 1340 the Bishop reclaimed the castle and then mortgaged it to the Planta family for 200 Marks. To discourage the Planta family from trying to completely annex the lucrative castle and tolls, in 1410 the Bishop mortgaged it to Jacob Perutt von Castelmur for 150 Gulden. Twenty years later the Bishop used a loan from the Salis family to buy out the mortgage and give it to them. In 1490, for the last time, the Bishop gave the castle to Michel Pfannholz. However, he abandoned it in 1538 and left the castle to fall into ruin.
The castle ruins were repaired and cleaned in the 19th century by Baron Giovanni de Castelmur. In addition to the castle, he repaired and rededicated the nearby church of S. Maria (Nossa Donna). The church's bell tower is a Romanesque construction, but much of the church itself, including the nave are from this 19th century renovation. The church was first mentioned in 988.
The original fortification was a wall or letzi that straddled the valley between the Maira river and the castle hill. This wall, which was up to 3.7 meters thick, had a gate that could be blocked by logs if needed. The remains of this wall are north-west of the main tower. In the 12th century a square tower with a ring wall were built on top of the steep outcrop. This tower allowed a noble family to take up residence and changed Castelmur from a toll collecting station into a regional administrative center. The five story square tower was 12 m on a side with 2.4 m walls on the lowest story. Much of this tower is still visible. The castle church was built below the castle hill south of the main tower. At some point, a second tower was added on a tall hill south of the main tower. This building measured about 10 m × 10 m, though very little of it still remain.References:
The St Sophia's Cathedral was built between 1045-1050 inside the Novgorod Kremlin (fortress). It is one of the earliest stone structures of northern Russia. Its height is 38 m. Originally it was taller, for during the past nine centuries the lower part of the building became concealed by the two-metre thick cultural layer. The cathedral was built by Prince Vladimir, the son of Yaroslav the Wise, and until the 1130s this principal church of the city also served as the sepulchre of Novgorodian princes. For the Novgorodians, St Sophia became synonymous with their town, the symbol of civic power and independence.
The five-domed church looks simpler but no less impressive than its prototype, the thirteen-domed St Sophia of Kiev. The cathedral exterior is striking in its majesty and epic splendour evoking the memories of Novgorod's glorious past and invincible might. In the 11th century it looked more imposing than now. Its facade represented a gigantic mosaic of huge, coarsely trimmed irregular slabs of flagstone and shell rock. In some places (particularly on the apses), the wall was covered with mortar, smoothly polished, drawn up to imitate courses of brick or of whitestone slabs, and slightly coloured. As a result, the facade was not white, as it is today, but multicoloured. The play of stone, decorative painting and the building materials of various texture enhanced the impression of austere simplicity and introduced a picturesque effect.
The two-storied galleries extend along the building's southern, western and northern sides, with a stair-tower constructed at the north-eastern corner. The cathedral has three entrances - the southern, western and northern, of which the western was the main one intended for ceremonial processions. A gate standing at the entrance is known as the Sigtuna Gate (mid-12th century); according to legend, it was brought from the Swedish town of Sigtuna in 1187. The second name of the gate derives from the town of Magdeburg, where it was made. The two leaves are decorated with biblical and evangelical scenes in cast bronze relief. In the lower left corner there are portraits of the craftsmen who created this superb specimen of medieval Western European bronze-work. An inscription in Latin gives their names, Riquin and Weissmut. The small central figure - judging from an inscription in Slavonic - is a representation of the Russian master craftsman Avraam, who assembled the gate.
There is yet another bronze gate in the cathedral, called the Korsun Gate. Made in the 11th century in Chersonesos, Byzantium, it leads from the southern gallery into the Nativity Side-Chapel. Legend has it that the gate was handed over to Novgorod as a gift of Prince Yaroslav the Wise (c. 978 - 1054).
The interior of the cathedral is as majestic as its exterior. It is divided by huge piers into five aisles, three of which end in altar apses. In the south-western corner, inside the tower, there is a wide spiral in relatively small, modest buildings of the 12th - 16th centuries.