A Mystery

Updated post is below, but I'm searching for help on a part of Fenway I simply cannot figure out, and I would love to find some photos showing this actually existing. From the blueprints:




The portals down to the concourse are roughly highlighted in red, but there is one real outlier circled in yellow. There doesn't appear to be any concourse even near this part of the park, and I haven't been able to find any photos showing this even existing, however it has appeared in two different 1934 renovation blueprints.

Now, this could stem from a number of different situations. One, it was part of the 1934 renovations that simply weren't built, and just appeared on blueprints before being nixed. Second, this portal was part of the original 1912 park, but was filled in in 1934. Thirdly, it actually existed, and was filled in much later, in time with another renovation.

Option #3 would be the most interesting due to the new questions raised. Where did it go? When was it filled in? Are there concourses buried deep in the park that haven't been seen, or converted into storage?

Any photos, anecdotal evidence, and the like is deeply appreciated. Until I figure out what's going on, it's staying out of Vectorworks.