Hey, I was running a Forlorn Streets echo and when exploring the map to the very southmost, I happened upon a background structure with an interaction prompt that appeared for me on controller. I was intrigued and activated it, then it teleported me to a space with no visuals but invisible walls. I wish I had a screenshot of the prompt and the whereabouts outside but I wasn’t thinking too hard at the time. Here’s a visual; hope it helps.
PS: Actually I reloaded the map and found it again. Here’s a visual of the interactable.
PSPS I tried to find a game log but I never found it in files.