The triforce from the very beginng, since hyrule creation was into the sacred realm,
In these both games: ALTTP & OOT

In ALTTP are a leyends told by hyrule people that said that the triforce are inside in some building, some people think that this buildings are in the graveyard, in the death mountain, or the dessert etc... but the only true thing is that in hyrule are some buildings that was be used like a gates to entered into the SR, like the temple of time in OOT. the Triforce isnt inside this building this building conducto you directly to the SR,to the Temple of light where the triforce is.

The triforce never are resguarden in hyrule before OOT or ALTTP, in hyrule only are gates,portalS thAt conduct u to the sacred realm, the SR are another world/dimension.