The Napoleonic Powder House was built by Napoleon at the beginning of the 19th Century as a powder magazine. It replaced the previous circular Venetian building that had and obsolete and not very functional dome roof. Using the squared stone from Medea, the French built a perimeter security wall.

The interior, which has a single compartment with a barrel vault, was divided by a floor with beams, a drier upper floor for powders and a warehouse on the ground floor. Along the walls there were – and there are still – ventilation cracks.

Nowadays, the structure hosts cultural events such as art exhibitions and conferences. In addition to this Powder House, there are two other very similar buildings in Contrada Garzoni and Contrada Barbaro.