In the new opening for Elbaph Batch 1 we briefly back through the history of the Straw Hat. We see it with Joyboy, Roger, Shanks, and of course Luffy. The weird part is in Roger's quick flash of the history sequence he seems to be on some unspecified island. Every other location in the montage is easily identifiable; Joyboy is with Emet, Shanks is in Windmill Village, and Luffy is on the Sunny(it seems to be in the scene where he tells the others his true dream) but it's not particularly clear where Roger is.
I'm curious what others have been thinking about this. My immediate thought was Laughtale but it'd be ridiculous to reveal it's landscape in an intro before it's own arc so maybe it's Lodestar? We know it can't be Elbaph since it looks nothing like the Underworld and if it were the Sun or Heaven Realm the branches of the tree would be clearly visible. Any other ideas?