Fort St. Philip is a decommissioned masonry fort located on the eastern bank of the Mississippi River, about up river from its mouth in Plaquemines Parish, Louisiana. It formerly served as military protection of New Orleans, Louisiana, some up river, and the lower Mississippi. The first fort on this location "San Felipe", was constructed in the 18th century during the Spanish control of Louisiana. It was declared a National Historic Landmark in 1960. In the 1930s the fort was used as a tanning factory. This explains the old railroad tracks and fire hydrants. [citation needed]