I lived on the Upper West Side for years, and walked along this stretch of Columbus Avenue countless times, but I don’t think I ever noticed this plaque until I passed it by a few weeks ago.

Apparently nobody knows who Sylvia was or why the building was named after her. The best guess referenced in the link is that it is the Sylvia of “Two Gentlemen of Verona,” as a building across te street is named Viola, who could be from “Twelfth Night.”

I was mostly intrigued by the design of the plaque. It almost looks more like a crypt plaque than a building name.I doubt Sylvia is interred there.  But who can say with certainty that she is not.