Hello! Not sure if this is a bug necessarily, especially because the game is filled with secret walls that you basically no-clip through, but there's a spot in the Forest Transition area where it looks like it leads somewhere but it's just a dead end. It seems unintended to me, though I could be missing something:
Another minor oddity is that the area near the Adventurer Idol has a mysterious hitbox that extends a single row and you can hurt it with anything that does normal damage (e.g. attacking, mining, harvesting, fishing, etc). I imagine it's impossible to actually destroy, but I tried anyway!:
