Built in the 12th century by Pedro Álvarez de Soutomaior it is one of the most important castles in Southern Galicia. Its origins can be traced back to the reign of Alfonso VII, when a military construction was built in a strategic location in the town of Soutomaior. On a hill at 119 metres above sea level at the bottom of the Ría de Vigo, the castle was near the coast but protected against the sea incursions of the Normans, the Turkish or pirates. It also controlled the communications from north to south, and dominated the valley of the Verdugo River, from its confluence with the Oitavén River to its mouth.
In the 15th century, the defensive tower was turned into a two-walled complex. At that time, the castle was closely linked to Pedro Álvarez de Sotomayor, popularly known as Pedro Madruga, who held the title of Count of Camiña, Viscount of Tui, and Mariscal of Baiona. There seems to be evidence that Cristopher Columbus and Pedro Madruga were the same person, since they had friends and rivals in common, and about one hundred places discovered in the New World were renamed with place names from As Rías Baixas.
Over history, Soutomaior was the centre of feudal power, the setting of many battles, and the summer residence of the noble families. Today, it is a historic site open to the public with a garden recognised as an International Garden of Excellence. The current magnificence of the building has been the result of several renovations and alterations.
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.