I mean the sort of fog of war old RTS and games like BG 1+2 (these game would only be half as long if you didn't wander around aimlessly around those oversized maps in order to find stuff) had where you line of sight was laughably short and you couldn't see anything.
Most modern games do it better, though I'm still not a fan of the mechanic. anyway, whenever someone mentions it I get flashbacks from the nineties where I was stuck for hours because I still had to kill one guy who hid somewhere in the edge of the map.