Before coming under the jurisdiction of the Lithuanian state, Panemunė Castle was without an attentive or wealthy owner for almost one hundred years. Long empty and neglected, today it is the most authentically preserved 17th-18th century residential castle in Lithuania. The castle, adorned with defensive installations and surrounded by what appears at first glance to be a protective series of bodies of water, was nevertheless not intended as a defensive fortress. It is a typical renaissance feudal castle of the early 17th century, designated not only for representation, but also to protect its inhabitants from the military conflicts that resulted from feuds erupting between noblemen, as well as to commemorate its owner's ambitions and his desire to emphasize his independence. It is doubtful that the building, albeit characterized by large architectural forms with defensive towers and embrasures, was ever used for military purposes. Certain lay and religious buildings of the 15th-16th centuries did feature similar elements – including embrasures featuring cross-shaped cutouts at the top of the opening.
The castle architecture features elements of the renaissance, baroque and classicist styles. Many owners oversaw reconstruction works, during which the castle's image was often changed, however none of them ever fully restored the full architectural ensemble.