It really blows my mind that they built a suburban style interchange in the middle of the city. I guess it shouldn't seeing that highway engineers did that everywhere but still.
Yes, indeed. That is the former New York, New Haven and Hartford Railroad station called "Back Bay." It was built in 1899 and rebuilt in 1929. On the ends of the new Back Bay, there are some remnants of the original station that they left for historical sake and replicated into the arcade along Dartmouth.
I also love that photo because all of that huge swath is now Copley Place too.