Calvin and Octavia didn't write a lot of description about Frankfurt, but there was a list of places with an "X" marked next to some. I took that to mean that they visited the places that had the "X." It wasn't too much to go on, but it was something. The issue (or the interesting thing) is that Frankfurt would hardly be recognizable as the same city today. It was significantly damaged in the war, as well as now being a a fairly huge city with skyscrapers and lots of new construction. I decided to do my best with their list, and otherwise just wander and see where the day took me. I ended up spending a fair amount of time in the Städel Museum, which had a great photo exhibit up called "Fotographien Werden Bilder" (Photographs Become Pictures), about Ernst and Hilla Becher and the students they taught who went on to become well-respected photographers in their own right: Volker Döhne, Andreas Gursky, Candida Höfer, Axel Hütte, Tata Ronkholz, Thomas Ruff, Jörg Sasse, Thomas Struth and Petra Wunderlich. I also spent a good amount of time with their contemporary collection, which is housed in an amazing underground gallery that is lit via skylights that are embedded in the courtyard behind the museum.

Here is the list from Calvin and Octavia:

X Mr. Jugel, Bookseller
X [. . .] Bethmann, Banker
Pipes, Toys, Caps, Stock
Opera — Theatre
Shoe Store — soles
X Madame Rothschild
X Baron Rothschild
X Jews Quarter
X New Streets: Zeil, Mainzer Straße
X Dom [cathedral] X town House or Römer
X St. Les
X Museum of Pictures
X Library open Tuesday 11 to 12
X Where are Luthers shoes
X Goethe “House F” No. 74 Hirsch Graben
X [. . .] Gate — Synagogue
X [. . .]’s shop on Dom Platz — maps
X Tacchi glass shop in the Zeil
Paper at Jugels in the Hotel

And here are the places I managed to see. (I also saw the Zeil, which is a big shopping district, but didn't take any photos, and I saw Bethmannstrasse, which is named after Bethmann, and his bank still exists today, as well.)