Atlantic Avenue Tunnel of the Long Island Rail Road is an abandoned railroad tunnel beneath Atlantic Avenue in downtown Brooklyn, New York City. When open, it ran for about 2,750 feet (830 m) between Hicks Street and Boerum Place. It is the oldest subway tunnel in the world. It opened on December 3, 1844 and was finished by January 1, 1845. Atlantic Avenue Tunnel was part of the first rail link between New York City and Boston, Massachusetts.