As you're flying with Tengri, you will find the land of Nazcaa as the large island in the southwest corner of the map. It was previously covered with fog, so you couldn't land at all, and you still won't be able to do so. You need to find a bird symbol on the ground on the eastern side of the island, which is where you can land with Tengri.
You now need to walk all the way to your next objective, but don't forget about the forage points and hidden chests, so use Seek Fortune if you want some of the chests. Once you reach what looks like a broken bridge, go in front of it until you can investigate the faded bird symbol. Use Rejuvenate to bring it back, which helps in reaching the next area.
With that out of the way, go up to the broken bridge and use Bridge to repair it. Go inside the unnamed area to see it's a town called Ara Memoriae. Once the little scene is over, go up to each flowerpot and put in one of the flowers from earlier. When that's done, go to the altar in the middle for some scenes. The way to the final dungeon opens up!
