So, here's my very simple map of Labrynna. It's unlabeled, but I'll go through all the dots and lines and everything below the map itself.
Starting in the top-left corner and going clockwise.
The tan area marks the Talus Peaks region. Simple as that. The mountain drawings are not canonical locations of or # of mountains. A river comes down out of the mountains. It is the main tributary of the main river. Name ideas? Is Lynna River too boring? Anyway, the blue dot on this part of the river is Restoration Falls, a waterfall covering the ancient Restoration Wall we know so well.
Next, the red icon is Symmetry City. Then the main branch of the river, followed by the Palace Ruins Dig Site.
The blue area is the Rolling Ridge Mountains. It's blue because it was in OoA-present, whose map I referenced heavily, as well as the past, and because it's nice. The two black dots along it are the towns I mentioned, Yoll and Ralfston. Yoll is probably the one closer to the Yoll region, because that makes sense. Also, Ralfston is named for Ralph, and is intentionally close to where Nayru's house was. Yay for referencing the game.
Then, we see a second river that rounds the Yoll Wasteland. It's barely on the present map, but it seemed a good way to keep the area soggy. Plus, there used to be a river to the north and west in the past, so that water had to go somewhere.
Crescent Island is obvious, and there's little to be said about it right now.
Back on the coast is the great Lynna City. The outline shows where it is, because I'm clearly not an artist. Ambi Tower only happened because Paint has various paintbrush shapes that suited my needs without effort. The island it connects to is Eyeglass Isle, and that bridge is new. The building is the now-ancient library. It's mostly a monument, as its books are moved to safer locations under care of Lynna U.
The blue dot in the ocean is Zora Village (City now?).
Then, we get the sandy beach coast and the Fairy Woods, though I don't really like that name. Of course, if the name stuck, Link could run into a Great Fairy there, so that might be nice. Just north of that is Talusia, and that's my map.
Other stuff:
The OP mentions that Labrynna is home to 3 dungeons. The Yoll Wastelands scream out for a nasty one filled with gruesome dead things. The swamp is built over a graveyard that itself was built on an old palace, so there's tons of potential there. But it should be really creepy. I'm thinking Woodfall meets Under the Well. Imagine fighting a Dead Hand while stuck in the mud with a foot of filthy water everywhere, so you can't run.
The Palace Ruins also have potential, and must be visited in some capacity. Ruins are a bit obvious and not original, but they're also awesome.
As for other ideas, we have the Restoration Falls area. The falls are massive in height, but are fairly narrow, like the wall. There's also Rolling Ridge, with the Gorons, Crescent Island, though we have a Jungle Temple, the ocean, which could be home to any number of mysteries, and of course, 3 cities to explore.
I also imagine that the Rolling Ridge Mountains are taller than Talus Peaks. Talus feel older and more worn, while the RRs are taller, newer, and are capable of supporting snow at the peaks. That's why I drew them differently.
Also, if anyone has a great idea to fill that big empty middle of the map that at least sort of fits with the world and isn't completely out of nowhere, do share.