Tanglewood (あやかしの森 Suspicious Forest) is a dark forest directly northeast of Goma Plateau, situated between it and the mountain that contains the Abandoned Mine. It, along with Goma Plateau before it and Abandoned Mine after it, comprises the first three-part introductory dungeon to Golden Sun: Dark Dawn.
It is one of the earliest revealed locations for Dark Dawn, having been seen as far back as the E3 2009 trailer.
It has a negative reputation that comes about from being permeated by equally negative energy. It is said to transform at night, changing it into a wood that ensnares those brave - or foolish - enough to enter it at the dark.
Matthew, Karis, Isaac, and Garet must traverse the Tanglewood in order to reach Tyrell in the Abandoned Mine, and much is said about how it seems much more dangerous now than before. Various giant flowers stemming from the boss inside the mines obstruct their path, and after Garet demonstrates how to do so, Matthew uses the Fireball Psynergy to clear away several blooms and the roots they connect to.
Once you enter Tanglewood from Goma Plateau, a very long series of cutscenes transpire which includes a visual Djinn and Summontutorial, at the end of which Matthew and Karis will have had three temporary Djinn set on them each, three Venus and three Mars. Each of the three attack Djinn among them - Torch, Sap, and especially Shine - are incredibly powerful and useful at this beginning point of the game. Furthermore, Isaac and Garet will accompany Matthew and Karis into battle as uncontrolled "guest" characters that basically make the party invulnerable, and on the rare occasions they do something offensive they deal over 300 damage.
From your starting point, go through the winding path east and north to the lower right part of the purple lake with all the hoppable platforms. Hop left four times to get to a chest with an Herb. Hop back right twice, then hop north once, west twice, and north once to cross into the entrance to the screen above.
The next screen is filled with glowing red roots that force you on a linear path around and through, and has a large, red flower in the center that you would pass by on your way northeast. At this point, another lengthy cutscene will trigger, but you can choose one of two that are quite different from each other. Ordinarily, once you follow the linear path right past the flower and into the area northeast where there is a chest with a powerful Bramble Seed, you will get a cutscene in which your Fireball Psynergy demonstrates its ability to target and burn the flower, which will remove all of the area's roots. You can Fireball the flower before going northeast to the chest, however, which will cause a different cutscene to play instead. Once out of the cutscene, the lower left exit of the area is opened to take you back down to the previous screen, where burning another flower makes another shortcut. There is little point in doing this, however, so head to the northeast exit of the screen and Fireball another flower there to open up the way into the next screen.
The next large screen includes a maze of traversable green walls. Walk onto the green wall-path to your right and walk off it at its bottom. Just right of that is a four-way at roughly the center of the area; take the right fork and you will be led along a winding linear path all the way to the southwest corner of the area. Fireball the flower here to remove its root, then climb onto the wall-path north of that root and follow it up and right to its end. Hop right across it onto another wall-path, then go right a little more and hop north so that you are on the wall path surrounding the small plant near the northeast corner of the area. Position yourself just southwest of the plant and hop north to the wall-path with the stairs that goes down and leads you to the plant. Cast the Growth Psynergy to transform the plant into ivy that is climbed like a ladder. At the elevated portion on top of the ivy ladder, position yourself south of the elevated flower and Fireball it from a distance to remove its roots. Now climb back down and follow the purple-ground path around to the newly opened exit at the north end of the screen.The next screen is a purple lake with another hoppable platform maze, and two earth pillars that can be pushed off your platform into the water in designated spots. Push the right pillar two spaces right so that it falls into the water and lets you hop to the chest with an Elixir. Hop back and push the other pillar two spaces left and two spaces up. Hop up to the first platform, hop the two platforms right of that, hop up one platform, and hop left one platform. Now cast Move to remotely move the earth pillar above you down one tile so that it falls in the water and lets you hop north across it to the plant, which again you need to cast Growth on. Once you climb up the ivy, a small cutscene occurs, and enter the gaping entranceway into the Abandoned Mine.