Like Bahari Bay, you can earn an achievement for finding all the treasure chests in the Elderwood of Palia. Scattered throughout the various areas of the map, there are 15 chests for you to discover. This is where to find all Elderwood treasure chests in Palia.
Elderwood Treasure Chests Locations
Each treasure chest grants you at least one item as a reward. All of them will give you Treasure Chest x1, which can be gifted to NPCs, used on your Home Plot, stored away, or trashed. Opening all 15 treasure chests earns you the Elderwood Riches achievement, which rewards you 30 Renown.
Okanaa Bog Treasure Chest
Found on top of the ruins where the found quest Hair Today, Gone Today trigger is located. Contains Fishing Mystery Bag x1.

Mauvais Way Treasure Chest
This chest is on a ledge on the western side of the area.

Mauvais Way Treasure Chest 2
Finding this treasure chest means climbing up the ledge towards the blocked entrance to Zendruu Way. Follow an offshoot path to reach the chest. It contains Mining Mystery Bag x1.

Purple Reeds Treasure Chest
Found outside the southern exit from Elderwood Central Stables near stacks of purple crates. This crate has Sacred Flower x1. It also gives you the recipe for Flowtato Fries with Ketchup.

Deep Woods Treasure Chest
Located in a cave only accessible from a hole at the top. You get Foraging Mystery Bag x1.

Deep Woods Treasure Chest 2
This chest is found on one of the flower platforms in the Deep Woods. It holds a Fishing Mystery Bag x1.

Hidden Cave Treasure Chest
Found inside the Hidden Cave during the quest Like a Shiprunt. Can be revisited through the Beast's Lair entrance or the grate to the north.

Honeymiel Slope Treasure Chest
When you enter the Elderwood from Bahari Bay, head down towards the river. Go over the center bridge then up a slope to find the chest. It gives you a Hunting Mystery Bag x1.

Honeymiel Slope Treasure Chest 2
Head to the highest point on the Honeymiel Slope. You'll need to scale up a ledge to reach it. The chest is found in front of a tree.

Jenesse Pass Treasure Chest
The treasure chest is found in a corner of the area. You may need to follow the wall as a ledge can hide it from view depending on the angle you approach from. It has a Foraging Mystery Bag x1 inside.

Lilac Cavern Treasure Chest
Drop down from the ridge in the section with the two Shmole holes and the Umbraan Shrine. The treasure chest is found at the back. You'll get Mining Mystery Bag x1 upon opening.

Central Stables Treasure Chest
This chest is found on a ledge above the lanterns on the northern exit side. Contains a Hunting Mystery Bag x1.

Red Blossom Cave Treasure Chest
Head to the northeast part of the cave to find this chest. It holds Hunting Mystery Bag x1.

Red Blossom Cave Treasure Chest 2
Found in the western part of the cave close to the Okanaa Bog entrance. You'll need to climb up tree roots to find it resting on a small ledge near the stone wall.

Mitana Grove Treasure Chest
This treasure chest is well hidden under the left bridge. Go down the slope and check the reeds close to the wood platform to find the chest on a small patch of land. Opening it reveals an Insect Mystery Bag x1.

If you're having trouble locating any of the chests, you can purchase the Treasure Tracker relic from Elouisa's Artifact Store. It'll point in the direction of a treasure chest, but works at a short range.
And that's where you'll find each of the Elderwood's treasure chests. Once you're done with these, make sure to check out more of our guides for the game below.