Roger is Luffy's Kuina --- Share Same Dream
Shanks is Luffy's Koushirou --- Gave away Precious Item of Person above
Zoro's Joy Boy is still Hidden --- Ancient Samurai who used Three-Swords Style
Luffy's Mihawk is still Hidden --- Final Villain
The Person who made Kuina's Sword (Which was Inherited by Zoro) Left Wano (Land of Samurai) & Settled in Zoro's Home
Meaning The Person who made Roger's Hat Left Land of Joy Boy & Settled in Luffy's Home
Current Wano turned out to be Wano 2.0 & Original Wano is Underwater
So there is a Copy of Joy Boy's Kingdom & whoever made Roger's Hat Escaped it & Lived in Dawn Island
If Wano is Land of Sword Makers, then Joy Boy's Kingdom is Land of Hat Makers (It's also why Dawn Island is Full of Characters with Hats, as Luffy, Ace, Sabo all wore Hats, Garp was also Introduced with a Dog Hat & same for Revos Army ... etc)
Luckily Oda answered us who are these People who are fond of Hats more than any other Clothing, when He showed Ace make a Hat for Little Oars Jr. & also it was revealed that Oars went to Ice Continent without wearing any Clothes, yet the First thing He did when He was revived by Moria was to wear a Hat
Both these were Hints that Ancient Giants are related to Hats, why? cuz the one who made Roger's Hat is none other than Oars who escaped his Original Kingdom & established himself in Dawn Island, turning it into "Country of Villains"
Now if Oars is the one who made Roger's Hat, it means He did it for a Guest He befriended (Just like Calgara/Noland Meeting or Yamato/Ace), and He also made a Hat for himself as Part of a Promise (Again just like Calgara/Noland & Yamato/Ace)
It's also similar to how Kozaburo made both Wado & Enma (Wado ended up with Kuina, but Enma stayed in Wano)
Meaning Oars Straw Hat is still in his own Kingdom (Which again i remind, it's Joy Boy's Kingdom 2.0)
And luckily We have seen that Hat & it's in that Secret Place visited by Imu
For those who think that Place is in Mary Geoise, it's not necessarily, Imu can Summon himself just like Gorosei & He was seen going up the Stairs, not down, so that Hidden Kingdom can be anywhere
So where is it? It's in the Place where Oars Died & that's "Land of Ice"
When Oda was asked about which one is Colder, North Pole or South Pole (Answering Shanks/Buggy Argument)
He said that South Pole is Colder but then added "South Pole isn't Coldest Place in One Piece World"
Suggesting that He did create a Place meant to represent Coldest Ever & it's none other than "Land of Ice"
That's where Imu appeared with Giant Hat
It's not confirmed but if We assume that Moria found Oars Corpse near Land of Ice cuz it's in his Home Sea, then it should be "West Blue".
Do you know what else Moria took from West Blue? Thriller Bark! And it's Castle definitely matches the Room accessed by Imu, The walls around it even resemble Ancient Kingdom as drawn when Clover was talking about it, indicating that Moria actually stole a Piece of Ancient Kingdom 2.0 from West Blue that was hidden near Land of Ice. Which explains why Doflamingo was Ordered to Kill Moria
It makes Perfect Sense that Ancient Kingdom 2.0 is Hidden in West Blue (Where Shanks Originates From & also Bink's Sake Song)
And OG Ancient Kingdom ended up being Hidden in "Land of Ice" hence why Oars sought it before He died there
So the only way to find Joy Boy's Home (Aside from being Summoned there like Imu does) is to be able to resist & create a passage in Coldest Place Ever in One Piece, which explains why it's Near Impossible to Find or Recover, unless you have "Laboooon"!