Hylia's Realm

is a location in SS undefined. The location that would eventually become Faron Province's Sealed Grounds in the present time, Hylia's Realm is home to the Temple of Hylia, and the realm's outdoor area is the final area in the game that isn't solely a boss arena.

Features
When Link first steps foot outdoors in Hylia's Realm, one can easily see that, at this point in time, the Statue of the Goddess has only recently been removed from the realm. As such, Hylia's Realm mostly resembles its future counterpart prior to the statue's restoration to that area.

Although the sun shines when Link first sets foot into Hylia's Realm, the area quickly darkens as the realm becomes the setting of a Horde Battle unleashed by Ghirahim, in which Link rushes down the path, fighting off standard enemies, until he eventually reaches Ghirahim. Link ultimately defeats Ghirahim, but not before the ritual Ghirahim was performing is completed, unleashing Demise from his seal. Once Demise leaves the area for the game's final boss arena, Link can use the game's final Bird Statue, situated at the bottom of the realm, to save his progress before taking on the game's final enemy.

Trivia

 * Given what Hylia's Realm becomes in the future, it's possible that the final Bird Statue eventually becomes the first Bird Statue Link encounters when dropping into the Faron Province for the first time.
 * Despite the area behind the Temple of Hylia appearing on the map for Hylia's Realm, players cannot visit that area in the past.