Castle Clinton National Monument, in Battery Park at the southern tip of Manhattan island, New York City, was authorized in 1946 to preserve a brick fortress that had been built there in 1808–11, directly prior to the War of 1812. The 0.4-ha (1-acre) site has served many functions since the fort was built. After the Civil War it was called Castle Garden and used as an immigration center, receiving more than 8 million immigrants before the larger Ellis Island facility began operations in 1892. From 1896 until 1941 it was the home of the New York Aquarium, which is now located in Brooklyn's Coney Island. In 1986 it was renovated to serve a dual function: the museum offers a view of history at a time when the new nation was preparing itself for a possible invasion by Britain, and the visitor center provides information on all the units administered by the National Park Service in the New York metropolitan area.