Region Key (details below)
Great Hyrule Forest (The Lost Woods, Neo Hytopia)
Central Hyrule, Eldin, Tabantha, The Ridgelands (Lindor, The Mountains), Lanayru Great Spring, West Necluda,
East Necluda, Gerudo Highlands, Gerudo Desert
Other Lands - Holodrum (Tarm Ruins, Temple of Seasons, Goron Mountain, Mt. Cucco, Holodrum Plain, Natzu Prairie, North Horon, Graveyard), Subrosia
Other Lands - Labrynna (Sea of No Return, Crescent Island, Zora Village, Deku Forest/Wing Dungeon)
Regions that cannot be selected
Hebra
Akkala
The Ridgelands - The Northwest Hyrule Plains
Lanayru - Lanayru Wetlands
Lanayru - Ploymus Mountain
Great Plateau
Faron
Other Lands - Holodrum (Spool Swamp, Woods of Winter, Horon Village, Samasa Desert)
Other Lands - Labrynna (Lynna Village, Rolling Ridge, Skull Dungeon)
Great Hyrule Forest - The Lost Woods
Surrounded by Lake Mekar, borders Hyrule Field to the south, Hebra to the west, Neo Hytopia north, and Eldin Canyon east. Home of the Kokiri, Deku Scrubs, and Skull Kids, also prowled by Gohma.
If you choose this region, you will be playing as the leader of the Kokiri, and will have to secure it against the Deku Scrubs and Skull Kids, and outsiders, before you can expand.
Great Hyrule Forest - Neo Hytopia
Would become Thyphlo Ruins in the distant future; North of Lost Woods, borders Hebra to the west and Eldin to the east. Home of the Hytopians, often besieged by Aeralfos from the Drablands, as well as Fire Wizzrobes.
If you choose this region, you will be playing as the leader of the Hytopians, and will have to secure it against outsiders, Fire Wizzrobes, and the portal to the Drablands, before you can expand.
Central Hyrule
Dominated by Hyrule Castle and exclusively populated by Hylians, but also prominently features Lon Lon Ranch. Landscape occasionally menaced by Peahats.
If you choose this region, you will be playing as King Hyrule, soon-to-be father of Princess Zelda.
Eldin
Consists of Eldin Canyon to the west and Death Mountain to the east. In between is the civilization of the Goron Tribe. The western and eastern portions are largely occupied by Talus and Dodongo.
If you choose this region, you will be playing as the leader of the Gorons (who, to be clear, is not Biggoron; think like Darunia or Daruk).
Tabantha
The Tabantha Frontier is home to Lynels. It is surrounded by Tanagar Canyon to the east and south, chasms to the west, and the mountains to the north.
If you choose this region, you will be playing as a great Lynel warrior and hunter, who yearns to unite Hyrule's mightiest people against the quarreling small folk. You won't have much of a following to start, but each Lynel is worth a small army of Hylians.
The Ridgelands - Lindor (centered on Ludfo's Bog)
Lindor, specifically Ludfo's Bog and the Seres Scrublands, is mainly occupied by Lizalfos. Choose this region, and you will play as their leader.
The Ridgelands - The Mountains characterized by Satori Mountain, Washa's Bluff, Illumeni Plateau, and Nima Plain.
The Mountains are occupied by Bokoblins and Octoroks. Choose this region, and you will play as an aspiring Black Bokoblin who wishes to unite his quarrelsome people and lead their forces in a glorious conquest.
Lanayru - Lanayru Great Spring
Home to the Zora people, bordered by Akkala and Eldin to the north. Choose this region, and you will play the Zora King, recent father of baby Ruto.
West Necluda
Home to the Sheikah of Kakariko, but also to the Moblins, who live in the mountainous lands of Quatta's Shelf and Pierre Plateau, and war over Rabia Plateau and Lanayru Heights with the Lizalfos.
If you choose this region, you have two options: play as a youthful Impa, who has newly received command of Kakariko village from her grandmother, and fight off the Moblins and Lizalfos so your influence can expand beyond these borders...
...or play as a Moblin chieftain looking to make himself King, take Necluda for himself, and reach the Moblins worldwide -- they will either bow, or perish along with everyone else; as the Sheikah soon fall under the influence of Hyrule, you likely will not repel them, but you can keep them confined to their little village and their narrow, dangerous route to the Kingdom, while you slaughter those Lizalfos scum.
East Necluda
Home to the Sheikah of Hateno (formerly known as Tolemac, which I'm aware is not canon, but the map of Tolemac syncs up really nice to the Hateno region), but also to the Hinox. While the Hylians and Sheikah here live almost exclusively on the southern border shared with Faron, the Hinox dominate almost all the region, fighting with the Lizalfos and a few scattered Lynels over it.
The Hinox do not care about the piddly little Sheikah village on their border. Ignoring it, they instead have the daunting task of repelling Lizalfos and Lynels from Necluda, so the shadow of Hinox can spread over Hyrule. As their leader, you will consider it your right.
Gerudo Highlands
The more rugged, warlike Sheikah and the Gerudo have formed a sort of symbiotic culture here. They fight the Octoroks and Bokoblins for dominance. Their settlements are in Meadela's Mantle, Sapphia's Table, Taafei Hill, Karusa Valley, and the Great Cliffs.
If you take this region as your starting locale, you have a choice to make. Will you become the dread Master of these mysterious desert Sheikah, and pursue you own primal or occulted desires (whether the local Gerudo bend or break)...
...or will you take up the role of a stubborn Gerudo vai who commands the people here, oust the local Sheikah, and determine for yourself whether the lowlanders are your friends, or just another obstacle? (side note: she will also be the mother of Ganondorf, unless you leave that to one of your subordinates)
Gerudo Desert
The Gerudo have two large and successful cities here, founded upon the oases that give them a way of life. When it was found that the mating calls of Sand Seals are a natural deterrent to Moldugas, the Gerudo made them a permanent part of their culture, to ward off one of the few things that could threaten their homes. No Bokoblins nor Moblins hunt here, it is too hot for Lynels, but some Lizalfos and Gibdos loiter a short trip from the cities.
If you choose this region, it is your task as Queen to keep the lowland Gerudo united, deal with the pestilent Lizalfos, Gibdos, and voes of all species. Will you unite with the highland peoples, or bring them to heel in your pursuit of power?
Other Lands - Holodrum (Tarm Ruins)
(the Holodrum regions are on a continent across the sea from Necluda, but which borders the same North Pole as Eldin by more accessible means; think like Russia and Canada)
Ruled by Onox, occupied by Lynels, Darknuts, and Octoroks, while the Ancient Ruins proper also contain Gibdos, Wizzrobes, a Manhandla, and other enemies.
If you choose to start in Tarm Ruins, here are a few things to know:
1. You will be playing as General Onox, who trained under Twinrova in anticipation of the Dark Return, the reincarnation of Demise's hatred as the prophesied Dark Beast.
2. You indirectly control several regions, but the Dungeon Bosses serving there are spurious cravens, like the Manhandla watching the Ancient Ruins for you. After you tame it and re-assert control of Tarm Ruins, seek out Spool Swamp, Holodrum Plain, North Horon, Woods of Winter, Mt. Cucco, the Graveyard, and the underworld called Subrosia.
3. Though your true form is that of the Dark Dragon, it is very difficult to take this more convenient guise and focus your powers, without the direct aid of Twinrova. They have recommended you wait to unleash it until the Hero of Skyloft reincarnates and comes your way, or a threat of similar strength should arise.
Other Lands - Holodrum (Temple of Seasons)
Watched over in peace by the Sages of the Seasons. Ordinarily peaceful, a small order of hermits not known to interfere in political affairs. Under your leadership, perhaps they could purify the land's dark dungeons, or even turn the inhabitants into servants of Light, and use them as an army to secure peace in the land. After all, you control the Seasons -- who could hope to stop you?
Other Lands - Holodrum (Goron Mountain)
Home of the Gorons. Turn out the monsters roaming the peaks, and your conquest of the lowlands will be easy.
Other Lands - Holodrum (Mt. Cucco)
Sunken City to the south is inhabited by Humans, but the mountain proper belongs to Moblins. Contains Dancing Dragon Dungeon, which contains Gohmas, Stalfos, Wizzrobes, and an Agunima, and many other enemies.
If you take Mt. Cucco as your starting region, you are a Fire Wizzrobe trained under the great Agunima. It is your dream to grow powerful enough to slay the Gohma swarm, drive out the Moblins, and take Dancing Dragon Dungeon for yourself. After that, the sky's quite literally the limit!
Other Lands - Holodrum Plain
Sparsely inhabited by River Zora, other enemies scattered about. Contains Unicorn's Cave, which is full of Darknuts, Gibdos, a Syger, a Digdogger, and other enemies. Controlled indirectly by Onox.
If you take Holodrum Plain as your starting region, you are a Darknut with ambitions on slaying the Syger, weaponizing the Digdogger, and claiming Unicorn's Cave as your lair, beginning your dominion over Holodrum.
Other Lands - Holodrum (Natzu Prairie)
Inhabited by Moblins. Play as the Moblin King, master of explosives, and send out your forces to make a name for yourself in Holodrum. But beware of Onox's forces!
Other Lands - Holodrum (North Horon)
Inhabited mainly by Octoroks and River Zora. Contains Gnarled Root Dungeon, which is full of Moblins, Gels, Zols, Stalfos, an Aquamentus, and other enemies.
Play as the Aquamentus, a lowly dragon who aims to become stronger than the feared Dark Dragon, Onox, and leave this tomb under a Gnarled Root. Send out your Stalfos, purge the Moblin invaders, and search the land for the secret to Onox's devious Warlock form. Once you have that, the Essences of Nature and the Temple of Seasons will be yours.
Other Lands - Holodrum (Graveyard)
Infested by Ghinis, but otherwise uninhabited, on the surface. Contains Explorer's Crypt, inhabited by Wizzrobes, Darknuts, Stalfos, Poes, a Gleeok, and many other enemies.
If this is your choice of starting locale, you play as the Poe Sisters, a ghostly coven of witches who seek an answer to bewitching the Gleeok, wresting the Crypt from Onox's influence, and haunting Holodrum until the answer to a Spell of Evernight can be found. Perhaps the answer lies in controlling the Season of Winter, but that's a long way off.
Other Lands - Subrosia
A plane between Holodrum and the Twilight World, inhabited by Subrosians. Contains Sword and Shield Maze, inhabited by Darknuts, Wizzrobes, Gibdos, a Frypolar, a Medusa Head, and many other enemies.
If this is your choice of starting locale, you play as the Subrosian Mayor, who wants to start up a booming economy on Subrosia's plentiful ores and industry, but is held back by the threat of Sword and Shield Maze, indwelt by the Medusa Head in the name of Onox. Perhaps the surface world holds a secret that could turn the tides, and give Subrosia liberty from that den of unkillable monsters!
Other Lands - Labrynna (Sea of No Return)
(the Labrynna regions are on a continent west of Tabantha, but which borders the same North Pole as Hebra by more accessible means; think like Russia and Canada)
Ruled by Veran, occupied by Biri and Anti-Fairies, while the Ancient Tomb proper also contains Arm-Mimics, Darknuts, Ghinis, Gibdos, Kyandokyans, Wizzrobes, Stalfos, a Ramrock, and other enemies.
If you choose to start in the Sea of No Return, here are a few things to know:
1. You will be playing as General Veran, who trained under Twinrova in anticipation of the Dark Return, the reincarnation of Demise's hatred as the prophesied Dark Beast.
2. Your aspirations to rule are outmatched by your obscurity. You got Ramrock to obey you and facilitate your escape, but the Dungeon Bosses in other regions will need convincing, before you can seek out the Oracle of Ages and rule this world as you were intended to. Seek out Crescent Island, Deku Forest, Yoll Graveyard, Rolling Ridge, and Skull Dungeon, before pursuing the surface dwellers.
3. Your form is weak. You inhabit a withered Gibdo husk, which cannot contain your power forever. Seek out a new host, something easy yet pliable, and begin the hunt for stronger and stronger bodies. You dare not take physical form as a Sorceress, or as your Dark Fairy self, because the Great Fairies will rise up and destroy themselves to ensure that your true power does not arise. Twinrova gave you shelter from this fate, warning you not to take true form unless all else had failed.
Other Lands - Labrynna (Crescent Island)
Inhabited by Tokays. Contains Moonlit Grotto, inhabited by Arm-Mimics and Zols, a Subterror, a Shadow Hag, and many other enemies.
Play as Knil, the Tokay with the bigly brain, who is big hero and ready to lead bombad Tokay army to the mainland. Island no good, scary Grotto there, too many nasties. Maybe come back and reclaim home, when Tokay army big and strong!
Other Lands - Labrynna (Zora Village)
Inhabited by Zoras. Play as the Zora King in service to Great Lord Jabu Jabu. Perhaps if he is fed properly, the nasty critters in his unfathomable belly will stop making him mad.
Other Lands - Labrynna (Deku Forest/Wing Dungeon)
Inhabited by Deku Scrubs, Moblins, a Swoop, and Thwomps, and other enemies.
Play as the young Maku Tree, and enlist Deku Scrubs sent by your uncle in Holodrum and your grandfather in Hyrule, to drive off the horrid Moblins, clean out the Wing Dungeon, and protect the forest forever.