Fallout 4 is full of hundreds of quests, some marked and unmarked, and a few of them are tucked away so well that a lot of players can explore almost the entire map without finding them.

It seems Bethesda might have hidden one of the best quests in the entire game a little too well though, as several gamers seem to have had no idea that it existed until now.

At least that seems to be the case, based on the comments in a thread discussing the side quest “Here There Be Monsters” on the r/fo4 subreddit.

“I didn’t even know this existed until I started my first survival run earlier this year,” commented user theinternetisnice.

“Somehow I just never ran across it. That periscope sure freaked me the s**t out.”

“I remember the first time I stumbled on this. Just wandering in the area and the periscope was going up and down and it caught my attention,” replied user UnkaRed.

“Would have never known about it had I not seen that and let the inquisitive side of me roam over to see what was happening.”

Now to be fair, it is actually pretty difficult to find this quest by just wandering around the map.

The Yangtze-31 submarine that you find the quest in is submerged underwater for a start, a decent swim away from the Shamrock Taphouse. You can see its periscope jutting out from the water, but you might just assume that’s a bit of random debris if you saw it out of the corner of your eye.

The quest really is one of the best Fallout 4 has to offer though, and completing it also nets you one of the coolest unique melee weapons in the game and a unique piece of nautical-themed armour.

Make sure you keep your eyes peeled next time you’re walking along the coast if you’ve yet to experience this quest for yourself.