Ellis Island is a federally owned island in New York Harbor that was the United States' busiest immigrant inspection station. From 1892 to 1924, approximately 12 million immigrants arriving at the Port of New York and New Jersey were processed there under federal law. Today, it is part of the Statue of Liberty National Monument, accessible to the public only by ferry. The north side of the island is the site of the main building, now a national museum of immigration. The south side of the island, including the Ellis Island Immigrant Hospital, is only open to the public through guided tours. The buildings behind it are, in fact, across the Hudson River in Jersey City, New Jersey, the tallest being the 79 story Goldman Sachs Tower, the tallest building in New Jersey.