The final part of the exhibition is located in three basement rooms, one of wh ich is 14th C. Gothic (with a vault supported by a central pillar) and two Renaissance rooms from the first half of the 16th century. Along the walls there are cannons, howitzers and mortars – ranging from small ceremonial cannons to huge outdoor ones. Two small cannons (from the mid 16th C.) cast by the Nurembegian founder, Oswald Baldner, commissioned by Sigismund Augustus, are examples of exquisite artistry. A collection of barrels which bear the coats of arms of Polish kings, hetmans and noblemen, the work of celebrated metal casters, is one of the most valuable in the country (alongside the Polish Army Museum collection in Warsaw) and are considered important throughout Europe.