10. Largest Basement: Grand Central Terminal

Grand Central M42 rotary

Grand Central Terminal has the largest basement of any building in New York City. The basement covers 49 acres, from 42nd to 97th Street. The entire City Hall building could fit into its depth with a comfortable margin of room to spare. Today, the MTA is about to complete an ambitious project of bringing Long Island Rail Road trains into the terminal via the East Side Access Project, making Grand Central even larger and deeper.

The East Side Access tunnels will be the deepest train tunnels on earth, at 90 feet below the Metro North tracks and over 150 feet below the street. It will take 10 minutes to reach these tunnels by escalator, at their deepest point. Another secret of Grand Central’s basement? The power station that doesn’t appear on any maps or blueprints!