It was built by Bernardo Morando in 1582 to 1584, situated just north of the palace Arsenal was one of the first public buildings in the town. The building is 63 metres long. To the lower floor leads the external staircase placed above the portal. Currently it is a seat of the Museum of Weapons. On the ground floor there is a permanent exhibition of seventeenth-century armory which is “cold steel” weapons such as firearms, weapons, guns, and an exhibition showing the history of the fortress of Zamosc, along with a model of the city.