Located at the most southern tip of Manhattan Island and facing the New York Harbor, the park gained it name from the number of artillery batteries that once were placed to protect the settlement. Castle Clinton was built in anticipation for the War of 1812. Between the years of 1855 – 1890 the castle was used as the first immigration station where more than 8 million immigrants arrived and were passed through the doors. Castle Clinton also served many other purposes and not just as an immigration center, but as the New York City Aquarium that at one time saw more than 5,000 people a day. Once the aquarium closed its doors at Battery Park and moved to Coney Island, the Castle was then restored by the National Park Service (NPS). It later reopened to the public in 1975.
Today, Castle Clinton National Monument serves as a home to the ticket office for Statue Cruises.