Originally Posted by
Ferdinand NYC
The tunnel is just south of Grand Central, in the 30s. There is apparantly some kind of sound exhibit in there. But, when I found that you couldn't ride through, I lost interest.
Do you mean the short, dark, ascending underpass-like part that leads up to the Park Ave. Viaduct (when riding southward from uptown along Park ave.)? If so, all cars and bikes can run on it. Walking would actually be dangerous. I'm not aware of any other tunnel.