Say what Tarq? You're the fanciest of any of us here!
Conditioning and hidden places, huh...that's a pretty interesting thought. Hmm....
In Star Ocean...3, I think. They actually have a map that starts out dark (fog of war) until the player reveals it. Now, this is the weird thing about it. There's a thing called "Map Completion". There's a gauge/bar/percentage that goes up the more the player reveals the map. When it gets to 100%, the player gets a reward.
I....sort of doubt if the mechanic's good/fun though. When I was playing it, it was really really tedious. Especially because you'd have to walk along the edges of the whole map for that 0.5 % percentages. Not sure if that was intentional or a bug, but it was really annoying to do.
In other games, there's also a tool/key item that can be used on a map. It then says how many treasures the player haven't discovered yet. Again, I'm not sure if this is the way to go if you want to promote exploration. Feels kinda...artificial.