Four main islands to explore when Hawaii technically has eight? Hmm, something tells me the other islands could either be 1) Postgame material or 2) where you catch other legendaries. That extra island hanging off the island with the canyon seems rather suspicious. I'm willing to bet it's either 1) where you catch a legendary not Solgaleo and Lunala or 2) the location of this game's Victory Road. I can't find anywhere else on the map where the Victory Road could be.
Now to speculate what each island has, starting with island 1:
This is definitely the island where you start. The town in the middle looks like the starting village. The Rotom Pokedex in its mini trailer mentioned something about the Pokemon Trainer school, and I have a feeling its in the town directly beneath the starting town. My guess is that judging from the road to reach, it's probably going to be the "second town" you come across in your journey. The city is probably going to be the location of your first gym badge. I don't know what the town above it will provide though. The volcano could be a route location since it's based off the Diamond-Head volcano, which is extinct in real life.
Moving on to Island #2:
I can already find four major cities here where the next four gyms will probably be located. I think this is the second island you will explore. My guess is that you start in the city located above the lighthouse since it has a pretty distinct port. It also looks it's the city where the supposed resort/Water gym was located, that one building we saw from the first trailer of the games. The mountainous jungle located below is probably the route that leads to the to the lighthouse city. The resort with the beach is probably going to be a route, but I'm intrigued with the golf course behind it. Golf in Pokemon? That should be interesting to see. The city above the resort looks rather cool. I'm willing to bet that modern-looking building is the city's gym. Those water ponds located in the top left interest me though. I wonder what could they be?
Next up, island 3:
I can find already pinpoint two major cities where there will be probably be gyms: the one on the top left and the one on the top right. The top left city looks interesting. It gives me an Attack on Titan vibe with the walls. The one on the top right is just as interesting with dedicated Japanese garden space and the pagoda located at the tip. I have a feeling that pagoda is going to be the gym. Maybe it will be a Flying-type gym because of the height of the structure? That'd be cool to see, especially if the Flying-type gym leader dresses in traditional Japanese clothing and resembles Takumi from Fire Emblem Fates (I'd see him being a Flying-type trainer because of archery has air-like characteristics, and his bow has wind like patterns at the tips with wings at the center). OK, I shouldn't put my thoughts about Fire Emblem here since it's doubtful we'd even get a trainer who resembles a Fire Emblem character, but it was fun to think about the nonetheless. I also think that city with the pagoda is the one you'll visit first because of its distinct port, and you can see a boat headed straight for it.
Now, where could the 8th gym be located? I'm going to guess it's the supposed city located at the bottom center for now. Those born stuff located beneath the building in the trees are probably buildings, and the house in the trees is probably a gym.
That mountain in the middle is definitely based off Mauna Loa. It's probably the region's main mountain since Mauna Loa is supposed to be the largest volcano in Hawaii, and one of the largest mountains in the world. I wonder why there would be snow there though. I can't even tell whether or not it's supposed to be a town or some sort of research facility. I also wonder what's the deal with that stonehenge-like place with the water surrounding it.
Next stop on our tour: island #4:
There seems to be only own town/city here: the Pacifidlog Town lookalike where the boat seems to be headed (and probably the first place you'll visit in the island). In fact, this island looks rather... secluded.
I am willing to bet that canyon is where you will catch Solgaleo/Lunala. The part that gives it away is the cone-like mountain with the pedestial and the stairs located in front of it. It just screams "Solgaleo/Lunala's location" to me. I'm guessing this is where the climatic part of the story kicks in where the evil team begins to carry out their evil plan. It's large size looks pretty fitting for the final location you fight evil team.
But that what about the massive tree on the left and that lava-affected area on the right? They could also be potential location where you catch the legendaries as well. When we first saw Solgaleo in last month's trailer, it looked like it was summoned somewhere inside a tree, while Lunala looked like it was summoned within some sort of cave. That tree and the lava-affected area seem to match up with those locations...
Which begs the question: If the tree and the lava-affected area are where you catch the Sun and Moon legendaries respectively, what's the deal with canyon? It could be the region's Victory Road since it looks a challenging area to explore, but that ritual ground located in front of the cone mountain still looks suspicious. My guess then would be this where a ritual is performed to summon Solgaleo/Lunala to their respective tree/lava-affected area for them to be found. Let's give it some time and see which thought turns out true.
I already gave my thoughts what that extra small island could be a few paragraphs up.
And finally: Pearl Harbor:
I'm calling it now. This is the region's Pokemon League! Why would it be located on its own like this? It even looks so modern and grand that it just seems very fitting to be a Pokemon League. That tall white building definitely looks very fitting to be the Pokemon League. The only question then is this: What's the mansion-like building behind it supposed to be. I'm going to guess it is the champion's house for now, or it could be the port where you will be dropped off once you surpassed Victory Road (I don't see Victory Road being located here since there's no way it fit in such a tiny space).
Or maybe it's the new Battle Facility the hiker was talking about in Pokemon X and Y. That building looks like something that fits with the description "we have this Battle Facility like you've never seen." I'm not too sure about it though, since there doesn't seem to be any other location that looks like a Pokemon League building except for this one.
And like I said, this is definitely based off Pearl Harbor since the facility looks similar to the actual Pearl Harbor memorial. I guess that's another reason why it makes sense for this location to be the Pokemon League. The Pearl Harbor memorial is supposed to be a very patriotic and grand location in the United States, so that's just another reason it could be this region's Pokemon League. We'll see if I'm right in the coming months.
