Chests Location
In this Sea of Stars guide, you'll find the locations of all the chests to be opened during Part 5: Stonemasons Outpost.
When you complete Part 6: Wind Tunnel Mines, you can explore the Stonemasons Outpost to find several chests. Find them all to collect rainbow conches, dishes, equipment and other items.
Resources - Mushrooms
Once out of Malkomud's fortress, head left and jump to land in a cellar containing several mushrooms, all of which you need to collect in order to cook dishes that will come in handy during battles. To exit the cellar, simply head for the exit on the right.
Chests to find
Chests #1 and #2: You will then find yourself in a villager's home. Open the 2 chests in front of you to receive a Teal Amber Ore and a Brilliant Pearl. Activate the lever to descend to the bottom and exit to the outside.
Chest #3: To find another chest, head for the entrance at the top of the stairs (see image below). Once inside, head for the corridor at the top right. Use your skill to move the green crystal block to access the blue chest. Open it to receive a Rainbow Conch.
Chest #4: Another chest can be found in a villager's room on the left (see image below). Open it to receive an Ancient Molekin Coat.
Bringing water back to the village
Then head for the sewer, where water seems to be running out. To bring back the water, simply climb up and head for the entrance at the top (see image below). Once inside, use the ladder on the left and head for a mill on the right. Activate it with your skill and the water will return to the village.
Then chat to the person nearby who appears to be taking a bath, and you'll receive a Rainbow Conch as your reward.