The Kajaani Castle was built on the Ämmäkoski island of the Kajaani river in the 17th century. The castle functioned as a administrative centre, a prison, and a military strongpoint. The most famous prisoner in the castle was the historian Johannes Messenius, who was forced to live in the poor conditions of the castle from 1616 to 1635.
Construction of the Kajaani castle began in 1604 and was completed in 1619. At first the castle only consisted of a stone wall, two round towers, and wooden buildings at the yard inside the castle.
Count Peter Brahe ordered a second construction stage of the castle, which was started in the 1650s and completed in 1666. During this construction stage, many wooden structures of the castle were replaced with stone structures to form a fortress.
During the Great Northern War (also known as the "Greater Wrath"), Russian forces sieged the castle for several months, until it was finally forced to surrender because of lack of food, firewood and ammunition. Shortly after this, the Russians exploded the castle and its inhabitants were transported to Russia to be imprisoned.References:
The Erfurt Synagogue was built c. 1094. It is thought to be the oldest synagogue building still standing in Europe. Thanks to the extensive preservation of the original structure, it has a special place in the history of art and architecture and is among the most impressive and highly rated architectural monuments in Erfurt and Thuringia. The synagogue was constructed during the Middle Ages on the via regia, one of the major European trade routes, at the heart of the historical old quarter very close to the Merchants Bridge and the town hall. Many parts of the structure still remain today, including all four thick outer walls, the Romanesque gemel window, the Gothic rose window and the entrance to the synagogue room.
After extensive restoration, the building was reopened in 2009. On display in the exhibition rooms is an collection of medieval treasures discovered during archaeological excavations. This includes 3,140 silver coins, 14 silver ingots, approx. 6,000 works of goldsmithery from the 13th and 14th centuries and an intricately worked wedding ring of the period, of which only two others are known to exist anywhere in the world. A mikveh (Jewish bath) has been excavated close by (13th/14th century). The Old Synagogue, the Small Synagogue and two Jewish cemeteries together form a network of historical buildings and sites which vividly portray the role of Jewish life in the history of Erfurt.