Due to its strategic position, the Sobroso castle was known as 'the key of the Kingdom of Galicia'. The name of the Castle, and the village itself, comes from the Latin SUBEROSUM, in reference to the 'sobreiras', Quercus suber or cork trees that once surrounded it.
The oldest reference to Sobroso Castle dates back to 1096. The castle that stands today dates back to the 14th or 15th century construction consisting of 2 enclosures. The outer one is irregular and the entrance is made through a drawbridge, and the inner one is rectangular with its keep on its weakest side.
In the 15th century, Sobroso Castle saw the fight between the Sarmientos and Pedro Madruga, but after that the castle wasn't much active.
The castle was restored from its ruinous state thanks to the efforts of local journalist Alejo Carrera Muñoz, who in 1923 bought the ruins of the castle from the Count of Torre Cedeira. He carried out the restoration work single-handedly, without any help from local authorities, until his death in 1967. In 1981, the neighbouring municipality of Ponteareas purchased the castle from Carrera's only child, Zita Teresa Carrera Ferreira, for 30 million pesetas. From 1995 onwards, the local council began their own restoration work on the castle.
The castle currently houses a cultural and ethnographic museum.
References:Sigmaringen Castle was first mentioned in the year 1077 in the chronicles of Petershausen monastery. The oldest parts of the castle are concealed beneath the alterations made during the 17th and the 19th centuries. The secret of the earliest settlement built on this defendable rock will never be fully revealed: large-scale excavation work would be necessary, which the extensive land development renders impossible. Judging from the many Roman remains unearthed in the area around Sigmaringen, the 12th century keep known as the 'Roman Tower' could be traced back to a Roman predecessor.
The castle remains that have been preserved (gate, great hall and keep) date back to the Staufer period around 1200. The castle remains were integrated into subsequent buildings. The foundations of the castle buildings are to a large extent identical to the surrounding castle wall.
These remains give us a good idea of how the castle might have looked during the 12th century.