Hello everyone, I’d like to share an idea that, in my opinion, would enhance exploration and rewards.
Scatter unique chests throughout the world that grant access to equipment or real big treasures with many more coins and gems inside.
I believe this would enhance the satisfaction of finding a “real chest” rather than just a random one among many others.
Only problem with this is YouTube/Reddit/ every other social media. They would be ‘secret’ chests for about a day at most.
Not even sure about 1 day 
But the idea of some kind of hidden chest that appears if you do certains actions etc, could be interesting, something like you talk to a certain NPC while wearing a certain gear piece (like a ring for exemple since it doesn’t change the weight of the character) at a precise hour after killing a specific boss and that NPC gives you a hint for something hidden somewhere, like a small paper with a coded message etc, etc.
A hidden quest that gives you a hidden chest 
Or it could be buried treasure from one of the digging sites on a map. It could be pointed out from a weekly bounty or something and be at a random location each time on the designated map. .
That wouldn’t be a weekly bounty then 
But a special quest could be a good idea, I just think that it would be link to something like classes (like Class Weapons in WoW) and that it would be a bit against what NRFTW aim, or maybe just for trinkets. “The Mighty Legendary Hidden Forgotten Quest for the Ancient Even more Forgotten Ring that no one on Sacra know the existence except one person that nobody know something about” ! that would be hell of a name ! 
It’s can’t be helped. Someone has mapped the entire treasure map of Shallows, Mariner’s Keep, and Orban Glade not even one day after Wicked Inside. When they have no access to the game. So any secret (talk to “hidden” character, find the “hidden” chest) wouldn’t last long. Although for me personally, I like to explore myself rather than searching for guides.
If there’s any “hidden” reward, I prefer it to be locked by skill barrier. For example, a crucible where you enter as level 1 character with no item and consumable. With total of 20-30 floors, with miniboss every 5 floors. Every miniboss and the last boss give progressively better reward.
Yeah you got it there, without any guide I allready know where all chest are. You can’t help that whatever the dev do, there will be guide not much time after. That’s today games, people enjoy watching someone that give them everything.
I’m probably an old fashioned gamer, I rather spend countless hours search for something by myself than waiting for someone to give me what to do or where to go.
I quite love hidden quest / treasures / secrets, so both options are viable, when can even imagine a hidden quest unlock by completing a certain level of crucible or by killing a certain boss that only spawn during night time in crucible or something like that
But that is a choice for those who seek out that information; as with any other aspect of the game.
I can simply not consume that information and those secret chests would remain an element of discovery in my play.
Though because of replay ability, I think the way it should work is every area should have 3-5 secret locations where the chest containing the loot can spawn. And in each realm, which of those locations it gets placed is random among them.
This way if I am playing again in another realm, I can still maintain some of that discovery even on a repeat play-through.