The Watervliet Arsenal /ˈwɔːtərvliːt/ is an arsenal of the United States Army located in Watervliet, New York, on the west bank of the Hudson River. It is the oldest continuously active arsenal in the United States, and today produces much of the artillery for the army, as well as gun tubes for cannons, mortars, and tanks. It has been a National Historic Landmark (NHL) since 1966.