where some of his most important writing was done

In this house, after splitting up with Sonia, leaving New York and returning to his native city. His aunt was in one of the apartments here at 10 Barnes Street, and Lovecraft was in a different apartment on the main floor. (His parents were both long since dead, of course, both of them insane to various degrees.)

[ADDENDUM: The street number now seems to be 12, but you can’t miss the place if you’ve seen the photo. There’s a “for rent” sign on one of the apartments right now.]