Map Exploration Achievement

[Nate]

I feel pretty certain I've been to every place on the map, yet I don't have the achievement. Anyone have this issue themselves or know of an easy to miss spot?

[Melodia]

Frigit Island. You can get there by boat, but only after you finish Osvald's story. For some reason the game forgets you visited there when recruiting him.

[Nate]

I already went back there. That's why I don't know what I could be missing. I also just beat the secret boss from Octo 1 so I have that area too.

[Melodia]

In that case, study the map and see if there's any suspicious looking road ends and mountain openings etc.

The other spots that come to mind is the cave that's east of New Destla, you need to use the boat to get there. Has a boss that you need to bait with a fish.
Also the level 48 dungeon off the coast of Toko'hara in the port area.
And the level 16 area in the Canalbrine Bridge also in the water.
There's also the clock tower in Clockbank.

[Prota]

Have you been to the Curious Nest? That was the last place I needed, it's towards the southwest of the open sea guarded by a shark boss.

[Livy]

There are a few locations that aren't that visible on the map, such as two caves at the bottom of rivers.

[PhamTrinli]

Have you been to the forgotten gateway isle?

[Nate]

Thanks for some of the tips everyone. I can't believe I missed it since I got the chest at the entrance at the start of the game. The place I was missing was the Starfall Spring found in the Southern Cropdale Trail.

[Jedo]

For anyone who has trouble with this achievement, I added all the regions' screenshots (including the sundering sea) zoomed in and labeled them on my guide. I also used nested bullets so you can see which area another area is nested/hidden in (like Seat of the Water Sprite in Borderfall).

https://steamcommunity.com/sharedfiles/filedetails/?id=2938224161

1 area is gated by main story and another is gated by side stories.