Casimir III the Great erected a castle in Ko³o – most likely prior to the founding of the city – as part of an overall enterprise of strengthening the boundaries of the realm. Ko³o castle was mainly intended to protect central Wielkopolska from attacks by the Teutonic Knights. The fortified city played a vital strategic role for some 200 years.
It was established as a 55 m x 40 m rectangle, made of brick with stone foundations, with its longer side arranged on a north-east, south-west axis and enclosed by high crenellated walls.
The castle slowly fell into decay from around the mid-16th century. This was mainly brought about by changes to the defence system after the invention of firearms and artillery.
The entire length of south-west line of walls to a height of 4 m (supported by abutments), fragments of the walls of the short sides of the foundation, and the tower are all that remain of the onetime castle. The north-west section of walls, on the Warta side, have collapsed due to the foundations having been eroded by the flooding of the river.
References:The Château du Lude is one of the many great châteaux of the Loire Valley in France. Le Lude is the most northerly château of the Loire Valley and one of the last important historic castles in France, still inhabited by the same family for the last 260 years. The château is testimony to four centuries of French architecture, as a stronghold transformed into an elegant house during the Renaissance and the 18th century. The monument is located in the valley of Le Loir. Its gardens have evolved throughout the centuries.