The Temple of Hylia has two exterior doors, one in the front and one on the side wall. The front door unlocks when the plot says you're supposed to go through it, but the other door never got unlocked during my playthrough. The map initially depicts both doors using the same "locked" icon, and there appears to be a path on the other side of the side door, so it seems like there ought to be a way to go through it.
So, is there a way to unlock it, or is it just there for decoration?
Best Answer
As far as I know, it keeps locked while you're in the past. @Jeff Mercado seems to agree with me, and he seems to have gone through every pixel of this game. Furthermore, no walkthrough I could find mentioned any use to the side door.
As I see it, the door is there for consistency throughout the game, but does not serve an actual purpose in the past other than say "if there's a door in the present, then there has to be one in the past, unless someone went and altered the temple, made out of stone" at some point between the two times". Which brings us back to the path. Why would there not be a path on the other side? Why have a door that leads to nothing? This is of course speculation, but the path likely leads to Faron Woods and the Skyview Temple, as it does in the present. And since you don't need to access those locations in the past, the door remains locked. I suppose it also allowed the developers to not have to create a new, younger-looking location.