Moonstone Garden Collection Chests in Hogwarts Legacy are part of the 22 Feldcroft Region Collection Chests, and all of them are mandatory if you aim for 100% completion in the area. You gain access to the Moonstone Garden dungeon while completing The Centaur And The Stone relationship quest.
The Chests can be obtained during the quest or after because you can return to the dungeon anytime. The collectibles are very well hidden in the dungeon, and you’ll probably miss them without knowing where to look.
Where To Find the Moonstone Garden Hogwarts Legacy Dungeon
On the map below, I’ve marked the location of the Moonstone Garden dungeon. As you can see, you have to go to the southeastern part of the region, and the fastest way to do so is to travel to the Irondale Floo Flame and head west.
The dungeon’s entrance has many candles next to it, making it easy to spot. Now, head inside to find the two Moonstone Garden Chests.
Collection Chest #1: Behind a Wall With Symbols
Once you’ve entered the dungeon, go forward and, in the first room, destroy the stone door to the south using the Bombarda spell, then go through. A little further, you’ll find yourself in a grassy area where you must fight a Cottongrass Dugbog. After defeating the enemy, use Bombarda again on the eastern door and go further into the dungeon until you reach a room with a barred gate.
In this room, you’ll find the first Chest, but you have to complete a little puzzle. If you look at your minimap, the Collection Chest icon should have appeared on it, and if you follow it, you’ll notice that it’s behind a wall with two symbols: a trinity and a target. The trick is to find the same symbols on the room’s walls and pull the handles above them using Accio.
The target symbol is to the right of the Collection Chest wall, and the Trinity is in the northeastern corner on the other side of the room. Pull the handles above the symbols to reveal the first Moonstone Garden Collection Chest.
Collection Chest #2: In Front of a Stone
For the next Chest collectible, you must first open the barred gate. Follow the same logic you used to open the wall with Collection Chest #1, but this time, open the wall with a circle with spirals and target symbols.
Then go really close to the moth you just revealed and cast Lumos to make it follow you. Now, take the moth to one of the two bronze devices next to the barred gate. Next, open the wall with the circle with spirals and trinity symbols, then guide the moth from there to the remaining bronze device next to the barred gate.
Then cast Depulso a couple of times on each device, or moth spinner if you want, to open the gate and then go through. For the second Moonstone Garden Chest, you’ll have to stray from the main path and jump into the water. In the water, find the whirlpool to the southwest and dive by pressing the Square/X button on your PlayStation/Xbox controller.
Progress in the new area, and you’ll shortly be in a larger flooded room with two Cottongrass Dugbog enemies. Defeat the mobs before entering the water, then swim to the southern passage and follow it to reach the second Collection Chest in the Moonstone Garden dungeon. The collectible is in front of a stone on a patch of land.