Carto

1 - Pick up the Ghost Lily remains to the right, and keep walking right (east). Talk to the owl, and head to the top of the curve on the river and arrange your map so you're surrounded by a circular river (you need to be inside the circle)
2 - Talk to Chirb, arrange your map so you can reach the new tile. Pick up the two pieces by the campfire. Talk to the men, and move the new tiles to extend the path that you're on
3 - Enter the first new tile, locate the tree with a ribbon tied around it, place the other foggy tile connecting it to the path. Follow the ribbon to the next tile, and repeat this process until you discover 2 more map pieces
4 - Connect the map piece with the path on it and pick up 2 new pieces. Talk to the man and his bear
5 - Place a foggy piece next to the path, enter it, and do the same as you did in step 3 except this time, keep going in the direction that the dead tree is pointing. A tip here, as it confused me somewhat. You don't need to connect the paths up. Just connect the piece following the tree directly. So if the tree points up then just add the second piece above it (with no paths connecting).
6 - Collect the 2 map pieces at the end, place the one with the stone, pick up 2 more pieces there, and talk to the folks
7 - Connect a foggy tile, enter it, and follow the same process from step 3 but follow the direction that the trees are swaying
8 - Pick up and enter the new tile for another piece and a Paper Airplane then connect the 3 thick forest path tiles lining up the dotted path.
9 - Walk to the tree at the end, go inside, arrange your map so you can pick up a Worm. Exit with the green triangle exit location. Talk to the owl and man, enter the new tree with him.
10 - This next section is very difficult to explain, but your aim is to put that worm into a little hole. Once you've done that the map pieces then need arranging so that worm gets to a dirt pile. You'll have to play around with this but it shouldn't be too much trouble. There's only one combination.
11 - Once that's done you want to get yourself to the dirt mount which will provide an arrow, then you want to re-arrange the pieces to get to the green exit location (with the little white triangle).
12 - You'll have a new set of map pieces. Arrange a small tree diamond with 4 of the pieces making sure you're in the centre of one of those used tiles.
13 - Arrange your map to match the carving on the rock to look like this:

14 - Speak to the man in the middle. There'll be a long cut-scene (of sorts). Once that ends talk to all the men and then to the old man again. Choose nod, and then exit via the cave to the south of your location.

You'll exit out at the start of chapter 4 and your achievement should pop.

Click on the link and it will jump to chapter 3.

Welcome

For peoples who do prefer a text guide over a video here is a guide with pictures for Chapter 3 from "Into Indie games"

https://www.intoindiegames.com/carto-walkthrough-chapter-3/