Liikkala fort was built by Russians in 1791-1792 as part of the South-Eastern Finland fortification system. It was meant to defend the road from the Swedish border to Hamina, which the Swedish army had used to attack Hamina in the Russo-Swedish war in 1788. Liikkala contained two ground redoubts and four demi-bastions.
After the Finnish War (1808-1809) Liikkala was abandoned, because the border was moved far away to west. Restoration of Liikkala Fort has been in progress since 1980 as an employment project by the National Board of Antiquities and the Ministry of Labour. Nowadays there remains well-preserved ground walls and some ruins of the Russian barracks.
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.