The card looks old but it’s contemporary and was mailed in 2020 with three different stamps, two postmarks, and Priority label.   We were curious about the building, and are grateful to both Wikipedia and Google Translate for this (somewhat edited) information: “The Steinerne Haus , also called Haus Bornfleck in older literature, is a historic building facing the market (house address: Markt 44 ) which connects the cathedral with the Römerberg The stone house was almost completely destroyed by air raids on Frankfurt in March 1944 . Nevertheless, it was reconstructed in the early 1960s and today houses the Frankfurter Kunstverein .”  There’s a small abrasion along the reverse right edge.  Grade: 2