There has been a fortified hill in Lieto (“Liedon Vanhalinna”) from the prehistoric age. According to excavations, the castle has been in use in the Late Bronze Age (1500-500 BC), in Middle Iron Age (500-700 AD, contested) and in the Middle Ages up to the end of the 14th century, when it was replaced by the "new castle" in Turku harbour.
During the first crusade (ca. 1155) to Finland Swedish army fought heavy battles against pagan Finnish people to conquer Lieto castle hill. After the victory Swedish fortified hill with stone and brick walls to defence the new city of Turku and christianity against Finnish and Novgorodians. There were several buildings, outer walls and a watch tower in the hill. When the Turku castle was completed Lieto castle lost the military value and was left to decay. The latest record of the existing castle date from the year 1438.
In the 1956 private landowners donated Lieto hill to the University of Turku, which has used hill for the archeological training. Nowadays there are some few ruins left of castle walls and buildings.
Krickenbeck moated castle is one of the oldest on the lower Rhine. Its history dates back to the year 1104, when the castle was first mentioned. It is unclear why the old castle, which was certainly inhabited by Count Reginar, was abandoned or destroyed. In the mid-13th century the castle was moved to the current location. At the end of the 14th century the new castle belonged to the Counts of Kleve.
Johann Friedrich II of Schesaberg converted the castle into a Baroque mansion between 1708-1721. On September 7, 1902, a fire destroyed the entire mansion. From 1903 to 1904, a three-winged castle was built in the Neo-Renaissance style. Today Krickenbeck is a conference center.