The IND Sixth Avenue Line is a rapid transit line in New York City, part of the New York City Subway. It runs primarily under Sixth Avenue in Manhattan and connects various neighborhoods, providing essential transportation for commuters and residents. The line features several key stations, including West 4th Street, 34th Street-Herald Square, and Rockefeller Center. Opened in 1940, the IND Sixth Avenue Line was designed to alleviate congestion on other subway lines. It operates with multiple services, including the F, D, and B trains, offering connections to other lines and enhancing the overall efficiency of the subway system.