Staten Island is the borough that is furthest south. It’s separated from the majority of New York by the New York Bay, making it New York’s very own little island companion. To get to the borough, one can cross the Verrazano-Narrows Bridge from the city of Brooklyn or can cross in from three different bridges from New Jersey. One of the more popular ways into Staten Island is the Staten Island Ferry from Manhattan, which is free.
The reason it’s rather popular with tourists is because it gives them a good view of other popular sites for free - the Statue of Liberty and Ellis Island being two of them. For a more industrial feel, people can go to the west shore of Staten Island.