I'm well aware that each and every map you can choose from has a tiny beach at its northern hemisphere, which I thought of unaccessible unless you'd had a Permit (which comes at the very "end" of the game), this lead me to think that some kind of rare loot, fish, etc. could be found when accessed to it. For my surprise, I could reach it using the stairs, and nothing special happened. I even tried using bait in order to see if a rare fish spawned, and ironically a Horse Mackerel, one of the commonest fish in the game, appeared.
Anyone knows if this tiny beach has some purpose or it's just what I see? It's existence is really suspicious...

I think it's just there to be a neat little thing to find. like "oh! I didn't know I had this tiny beach up here!". people also really seemed to love the "private beaches" in NL (when there was a section of beach only accessible by swimming), so this might just be this game's version of that

Yeah I think people were mislead about the "private beach" being anything besides the only spot with a northern beach (pretty much), that one video where it's all dressed up nice and there's like an animal or two walking over there. Mine is behind a mountain lol. The 3rd level is back there, but I can reach the beach if I use the ladder and there's nothing back there. It might be fun to hide something back there is all. Create your own fantasy.

It’s for Redd

Double mislead! Lol.

Yeah it's where Redd docks his boat! Also, if you use bait you can def fish there! I've caught just about every kind from that spot!