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 settlement of Trepucó is one of the largest on Menorca, covering an area of around 49,240 square metres. Today, only a small part of the site can still be seen, the two oldest buildings, the talaiots (1000-700 BCE). Other remains include parts of the wall, two square towers on the west wall, the taula enclosure and traces of dwellings from the post-Talayotic period (650-123 BCE).The taula enclosure is one of the biggest on the island, despite having been subjected to what, by today’s standards, would be considered clumsy restoration work. This is one of the sites excavated around 1930 by Margaret Murray, a British archaeologist who was a pioneer of scientific research on Prehistoric Menorca.
The houses are perfectly visible on the west side of the settlement, due to excavation work carried out several years ago. They are multi-lobed with a central patio area and several rooms arranged around the outside. Looking at the settlement, it is easy to see that there was a clear division between the communal area (between the large talaiot and the taula) and the domestic area.The houses near the smaller talaiot seem to have been abandoned at short notice, meaning that the archaeological dig uncovered exceptionally well-preserved domestic implements, now on display in the Museum of Menorca.The larger talayot and the taula stand at the centre of a star-shaped fortification built during the 18th century.