In the park in front of the Museum of the Polish Army building, there is an open-air exhibition featuring a unique collection of armaments from the 15th to the 20th century. On display are artillery, armoured and naval equipment, aircraft, helicopters and missile weapons. Many of these artefacts are unique in Poland and even the world.

Among the artillery equipment noteworthy are the cannon barrels and their fragments from the seventeenth century. Among the eighteenth-century cannons the most valuable are: two murolom - twenty-four-pound French cannons from 1754 and 1757. The MWP's collection includes, among others: a British sixty-pounder cannon Mk I calibre 127 mm, the barrel of a Russian howitzer model 1915 calibre 305 mm (one of only two surviving examples in the world) and French howitzers - a siege howitzer calibre 280 mm (both surviving examples are in the MWP) and calibre 155 mm model 1917.

Also unusual sights are the giant shells for: French 400mm rail gun, German self-propelled heavy mortar 'Karl' calibre 600mm, and the largest German gun of World War II 'Dora' calibre 800mm.
The most valuable Polish armoured vehicles on display at the open-air exhibition of the MWP include the TKS tankette and the insurgent armoured car "Kubuś". The foreign vehicles used by Polish soldiers include the T-34 tank from 1942, the IS-2 tank, the Canadian version of the Sherman tank "Grizzly", the self-propelled howitzer "Sexton" and the SU-57(T-48) self-propelled gun, as well as the post-war BAW Soviet amphibious vehicle, the only one in Poland.