A major birthday in the city on Sunday — The New York City subway celebrates 120 years.

The system first opened its doors to riders on Oct. 27, 1904, with an initial 9-mile line that ran from City Hall to 145th Street in Harlem. Now, the system includes 665 miles of track and 472 stations.

The NYC Transit Museum is celebrating the milestone with an exhibit called “The Subway Is...,” inviting New Yorkers to consider the way the subway system has shaped the city.

Anchor Rocco Vertuccio spoke with the museum’s director, Concetta Bencivenga, about the exhibit on “Weekends on 1” Saturday morning.