After rescuing the Village Chief of Grass Valley, use the Brown Stone to go to the GreenWood Shrine.
Go to LostSide Marsh
When you arrive in GreenWood, you'll see that it's empty, just like Grass Valley was. Go to the east to reach an area full of monsters. This is LostSide marsh.
The first type of monster that you encounter in LostSide is the Mudpit. Kill the Mudpits to release a bird.
Continue on. Some Shaber dragons jump out of the water and onto the bridge, where they spit a fireball at you. They always jump to the same spot, so avoid walking there. They are not affiliated with a monster lair.
Walk across the topmost bridge, avoiding the Shaber dragon at the very end, to find a lair of Mudpits. Kill them to create a bridge. Then go back to the south and go west across the lower of the two bridges.
Go past the bridge that you created when you cleared the last lair. To the north is a lair that spews out more Mudpits. There are also Shaber dragons that leap out just below the lair, so be careful. When you clear the Mudpit lair here, you release a dog.
Now go back to the bridge that you created earlier, avoiding the Shaber Dragons on the way. Go east across the bridge. There is a blue building to the north. This is the Water Shrine. There are shrub monsters called Shrubbers. They walk around at random, but they might stop and stretch a vine toward you. You can't hurt them while the vine is sticking out. Kill the Shrubbers and open the lair to create a bridge to the Water Shrine. Go into the Water Shrine.