Opended in 1920, established by the statesman and military leader Marshal Jozef Pilsudski, it's Warsaw's second largest museum. The collection illustrates a thousand years of Polish military history -from the dark ages to the Second World War. While visiting pay attention to an extremely rare gilded helmet from the 10th century, which is said to have belonged to a Polish chieftain. It's worth knowing that the Museum's collection of hussars' armour is one of a kind. In the Museum's park (admission free) you can wander amongst tanks and planes from the Second World War.