In Ocarina of Time Ganon/dorf destroys Hyrule Castle & builds his own castle.
After the
OoT sages sealed away Ganon/dorf, a new Hyrule Castle was built.
When Ganon returned to Hyrule, the land & the castle were sealed away under
the Great Sea. In The Wind Waker, when Link visits Hyrule, everything is
frozen in time. This is Hyrule at the moment it was sealed, right before the
Great Sea arose to hide the land of Hyrule.
We KNOW that the Master Sword shrine under WW's Hyrule Castle was
built before anyone knew that Hyrule would be sealed away. And what do you
see in this picture?
OoT Ganon with his two swords is shown against a background of
OoT Hyrule.
Beyond Hyrule's northern mountain range we can see...an ocean!