A Talayotic period settlement (1000-700 B.C.) in Trebalúger was a spectacularly large talaiyot; it is 28 metres in diameter at its widest point. It has an elliptical layout and was built on a high rocky outcrop on the site of an earlier structure from the Naviforme period dating from 1350 B.C., with the bases of the pillars still preserved inside. At the front of the monument, near the entrance, you can see the remains of a ramp that led up to the top of the talaiyot. Around the outside you can see the walls of a polygonal structure, also from the Talayotic period, which has been damaged by the lime kiln built over it at a later date.
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.