Mattapan Theatre No. 18625 Billboard for Mattapan Theatre with trolley car at Mattapan Square The Mattapan Theatre, on River Street at Mattapan Square, was located where the parking for the T is now. No. 4311 Detail from plate 39 of the 1933 Bromley Atlas showing location of Mattapan Theatre where the arrows are pointing. Share this:TwitterFacebookLike Loading...