Taopo Swamp

Taopo Swamp is a rather large optional dungeon-style location in the center of East Osenia, south west of Yallam, which can be reached and explored in Golden Sun: The Lost Age.

Contrary to its name, most of the area of Taopo Swamp traversed is not in the swamp itself, but rather inside a series of caves and caverns underneath, including caves full of lava and hot steam vents. Strangely, it appears that no monsters can be encountered in the actual swamp section. Taopo Swamp is optional, but should be traversed if only to obtain the Venus Djinni inside. The area also contains many forgeable items.

Taopo Swamp is halfways dried up compared to what it was before the eruption of Mt. Aleph, the lighting of Mercury Lighthouse and Venus Lighthouse, and the return of Poseidon, which caused the climate to change and the oceans to warm up. Sunshine, the blacksmith from nearby Yallam, sometimes travels here to seek out and gather materials to craft and forge goods from, for the area is rich with such resources.

Walkthrough
Enter Taopo Swamp from the overworld, and run right to the next screen. Run up to the edge of the wooden plank facing the small stump, and use the Move Psynergy to move the stump left so that it falls into the swamp. Hop right and up to get to a place there there are three bushes against the wall, and cast Whirlwind on the leftmost bush. The small cave area inside it has a half-buried Tear Stone in it, which you collect by casting the Scoop Psynergy on it. Step back outside and climb down the stairwell into the swamp area.

The swamp area in the outside portion of Taopo Swamp is a non-solid surface that you can only wade through for about six tiles worth before you drown and reappear at the point of solid land you were at right before stepping into the swamp, and how close you are to drowning is indicated by how far into the water Felix is partially submerged. The various tiles of bubbling swamp water dotted along the surface of the swamp are "safe zones" that restore your "swamp walking distance", visually indicated by Felix rising to the surface. Starting from the top bubble, run straight down to a bubble, then run to the bubble to the left of that, then to the bubble left of that, then down of that, then shortly left of that behind the support poles of a plank, then southwest of that, and finally below that to reach the lower left stairwell. Exit off the left side of the screen to return to a part of the first screen where a chest containing a Cookie reposes.

Now starting from the stairwell into the swamp leading away from the Cookie chest, go back up to the bubble above that, then the bubble northeast from that, then shortly east of that behind the support poles of a plank, and now go to the bubble southeast of that, then straight to the bubble east of that, then northeast of that, then east of that, then above that, then east of that twice in a row, and finally south of that to touch down on land. The right side of this area has two cave entrances, one right nearby and one accessible by casting the Growth Psynergy on the nearby plant, and both lead to their own large interior quadrants that are entirely separate from each other, almost as subdungeons. Remove the bush from the nearby cave entrance to enter the first quadrant.

"Venus Djinni quadrant"
Proceed through the cave path until you get to the "main room" of this quadrant, where steam vents regularly blow out of holes in cave walls in a pattern that can be safely bypassed with proper timing. If you get blown down one of the cliff slides by a steam spout, you land in the floor below in an area where weeds that can be blown away by the Cyclone Psynergy reveal a Bramble Seed to pick up, and you can climb back up to the steam spout area via a nearby stairwell. At the end of this first steam spout area is an earth pillar that can be Moved one space left to block one steam spout, and this has the effect of extending the range of the steam spout behind a Venus Djinni that lies out of reach to the right of your current position.

Before completing the puzzle that will make the steam spout long enough to blow the Venus Djinni into the abyss below, head up and go down two stairwells that lead to another half-buried Tear Stone that is to be Scooped out of the ground. Return back up two flights and proceed right to the other set of steam spouts to the right of the Venus Djinni. Make it left past the steam spouts and reach the earth pillar to the right of the Djinni, and Move it two spaces right to block a steam spout. The Venus Djinni will be blown off into the floor below. Of the five possible cliff slides in the vicinity, slide down the second from the left to land on an elevated part that lets you hop onto the elevated part where the Djinni is. Save your game and battle it to earn the Venus Djinni Flower. Following that, slide down the cliff slide and Cyclone away the weeds to uncover a Mad Plant battle that will reward you with a Lucky Medal when it is felled. The entire quadrant is complete, and fortunately, casting the Retreat Psynergy will return you to the entrance to the quadrant rather than to Taopo Swamp itself.

Volcanic quadrant
Back outside the entrance to the cave quadrant that had the Venus Djinni and Mad Plant, cast the Growth Psynergy on the small plant to turn it into climbable ivy (temporarily switch classes to grant yourself the Psynergy if necessary), and follow its path to another lone bush concealing a cave entrance leading to the other main quadrant of Taopo Swamp. Whirlwind it away and enter, and go down one floor into the first main room below.

In the first main room of this cave complex, go down and right and follow the path to another room, and get past a steam spout. Shortly beyond that is a steam spout that regularly blows over a circular indentation in the ground; this indentation can be filled with water with the Douse Psynergy that can then be turned into an ice pillar with the Frost Psynergy, but you must be quick and well-timed in casting these two Psynergies and then hopping across this ice pillar, because the steam blast from the spout will remove your work whether it is a puddle or an ice pillar. The best way to go about this is to wait until the spout has just finished projecting steam, then open your Psynergy menu and cast Douse. As soon as Douse is complete, open your Psynergy menu again and cast Frost. As soon as that is done, run up the nearby ladder and hop left and up across it as fast as you can. From there, it is a linear trek west into the stairwell leading to the floor below, and ignore the Lash-able rope because that is simply a route back to the first main room of the quadrant as you go down a further staircase into the volcanic bottom floor of Taopo Swamp.

If you get blown down the cliff slide or slide down it on purpose for whatever reason, you will be forced to go through an optional part of the dungeon that strictly exists to bring you back to the first main room. If you drop down into the cave floor below, follow the path along south until you find a similar setup of a steam spout in front of a circular indentation in the ground, but with the difference that water constantly dripping from the ceiling fills the hole up with a puddle of water for you (this is designed to clue players in that the other circular hole they came across shortly before is supposed to be filled up with water too). As soon as the puddle is normal-sized, Frost it and hop right and up across it. The elevated doorway in the vicinity connects to the room with the Lash-able rope described in the previous paragraph, but this is a one-way exit that acts as a dead-end for you, so stay out of that room and slide down the left cliff slide and go up the stairwell to the left. Back in the floor above, simply climb up and push the earth pillar right so that you can hop across it and come back to the "starting point" of the quadrant's first main room, and now you can replay your steps to the first water puddle/ice pillar/steam spout puzzle to try passing it again.

When you come down to the lava-filled bottom floor of Taopo Swamp, head down to the flaming rock and cast Douse on it to turn it into a stone that can be Moved one space left, and doing so lets you hop down. Note the layout of this floor for later reference if it helps, but exit the screen off the bottom left doorway.

The next room has hoppable platforms across a large pool of molten lava which has steam spouts at certain points. Step on the first platforms and hop left once, up twice, and left once, and you'll be in front of a spout that will push you down along four conjoined platforms. You should run up against the spout until it temporarily subsides so that you can then hop onto the upper right platforms as fast as you can, and then hop along the path downward to the bottom part of the area. Hop right across two small lava rivers so that you face a flaming rock on the other side of a scenery rock, and cast Douse to cool it down and Move to move it one space up into the lava to turn it into its own hoppable platform. Retrace your hopping steps to the steam spout that blows you downward along the four conjoined platforms, and hop right, down, left, down, left four times, and down to reach the lower left chest containing a Vial. Make your way all the way back to the bottom section of the room to the right of the chest's area.

At the bottom right part of the lava room, hop across the lava river via the one platform, then position yourself on the platform facing another flaming rock. Cast Douse on that, then move that left so that it is repositioned by the flowing lava river and allows you to exit back into the upper screen. Continue up along the scattered earth pillars until you reach and face an earth pillar with a large boulder balanced on its top. Cast the Tremor Psynergy to drop the boulder onto the lava river, redirecting the lava river west so that it pours into the water lake, cooling itself and providing new solid ground on the upper right part of the lake to walk across. In order to get to this new ground, come over to the newly created flaming rock, Douse it, and move it two spaces down into the lava river to create a new platform to help hop across the lava river with. Walk across the newly formed ground on the water lake to access one floor below.

In the small room you descend down into, a flaming rock illuminates the room, and Dousing it makes the room darker - an important observation to make for the final room in Taopo Swamp coming up shortly. Push the cool rock down and head through the doorway below, and the subsequent lava-filled room has a winding but linear path to its exit at the southeast. In the final, rock-filled room of Taopo Swamp, Douse the flaming rock to darken the room, whereupon a small spot of ground to the northwest will light up. Inspect the spot and cast Scoop on this spot to earn Taopo Swamp's final treasure, a piece of Star Dust, a powerful reward if this dungeon is played earlier rather than later. Cast Retreat to reappear at the entrance to this cave quadrant, step outside, and cast Retreat again to leave Taopo Swamp.

Collectibles
First off, in the exterior portion, this can be collected:

Cookie: In the first exterior screen on the bottom, reached by the next screen to the right.

From the main exterior area, there are three cave entrances leading into the interior portions of Taopo Swamp, each with its own set of cave areas that don't overlap with each other.

Tear Stone: In the small room reached from the left cave entrance from the exterior behind a Whirlwindable bush. Half-buried in the ground, retrieved with Scoop.

Of the two cave entrances located close to each other at the eastern end of the exterior screen, the one on the lower right leads to a cave complex that contains, among other things, a Djinni:

Flower: In the room where this is visible, push the earth pillar west of it one space left and the earth pillar east of it two spaces right, and a burst of steam will push the Djinni off to fall into the abyss below. Then, you can drop down below into a position near it by sliding down the second slide from the right of the space the Djinni was just located at. Must be fought to be obtained.

Bramble Seed: Found by casting Cyclone on a small plus-sign-shaped arrangement of weeds. Tear Stone: Half-buried in an area of cave similarly to the above Tear Stone, but deeper into Taopo Swamp. The cave room in question is reached by entering the downstairs up and left of the area where Venus Djinni Flower is initially located.

Whereas the cave entrance to the visible upper left of the above cave entrance leads down into a volcanic basement level, which contains the following collectibles:

Star Dust: In the final room at the deepest point in Taopo Swamp, filled with many rocks, cast Douse on the volcanic rock in the center, and then go to the spot to the upper left that is now glowing, and cast Scoop on it to get this. Vial: In a chest in the lower left of an area with a large lava lake.

Trivia

 * Taopo Swamp is likely named after the real-world Taupo Swamp, a 60-acre swamp in New Zealand, supported by how both swamps are placed close to the southern part of their respective worlds. While Weyard's Taopo Swamp is located in Osenia, Earth's Taupo Swamp is located in the geopolitical region of Oceania.
 * The water you see dripping down into the large hole when you first enter the quadrant leading down into the volcanic portion visibly and consistently drips down similarly sized and placed holes in all subsequent floors. It is the source of the water drops that drip into the circular hole in one puzzle. The water eventually gathers into the small watery lake at the volcanic basement level of Taopo Swamp.