Huh. The well you encounter at the end of the pier section with Mari is different from the normal well entrance. Blatantly so. How did I never notice? Simply entering and then exiting the well will take you to the normal entrance. Maybe it's because this is still part of Forgotten Pier. Like if Forgotten Pier isn't some weird pocket space, this is what the original Deeper Well entrance used to be when Forgotten Pier wasn't forgotten, so they both connect to the same place since the original location was in-universe overwritten by the small lake that took the pier's place. That's definitely reading too far into it. It just feels odd to have these same rooms. Maybe it's just some kind of development quirk or something.