Each biome in Luma island has a mysterious shrine that can only be unlocked once you find the appropriate crystals, and depending on the biome you may need to find up to 11 crystals to get the rewards inside.

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Luma Island: Where to find all the Hot Crystals
Tepid Offering Crystals are mysterious items that you can find scattered around Luma Island. Here you can find them all and how to use them.
Although it may take some time to collect these crystals, it's worth it because the shrine contains Luma Eggs and rare rewards that you'll want to take. The Forest Sanctuary requires eight crystals to unlock, and you can find them all here.
Crystal Forest Gift 1 Location
The Crystal Forest presents the first of the Luma island located near the entrance to the Forest. When you enter, follow the path forward until you reach a small stone bridge – you should be able to find the Crystal underneath, but there's no way to get to it now.
Cross the bridge and turn right at the pond until you see the Mushroom shopbut do not follow the path down to it, but look for a small gap where you can move around the cliff. Follow the path, and you'll eventually find the Crystal.
Forest offers Crystal 2 locations
From the Mushroom Man shop, follow the path deeper into the forest until you reach the river that runs through it. To find the second Crystal, head north and look for a a small hole you can go through on the rocks near the cave.
The hole will be hidden by various bushes and trees, so it can be difficult to find this hole. But, once you get it, you'll find the Gift Crystal hidden inside along the cliff.

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Forest offers Crystal 3 locations
To get to the third Gift Crystal, you need to go to the other side of the river in the forest. If you are entering the forest for the first time, the path will not be straightforward. From where you found the second Crystal, go to the a cave nearby. You can go through this cave without a torch, but there are some dark places, so it's better to take some with you just in case. After your journey, you will find yourself on the other side of the river.
Go around the pool and follow the path south until you see a color puzzle to the right of the road hidden in some trees. Follow the colorful puzzle path for a while and make sure you hug the wooden wall to the east. When you can turn east (left, if you came from the colored puzzle) do so, and you should see the Gift Crystal waiting on a small hill. in front of the broken stairs. You need 3 forest trees and 5 reeds to build the stairs, and you will get the Crystal.
Forest offers Crystal 4 places
Continue south from where you found the last Gift Crystal until you find a blue crystal on top of a pillar behind a small hill. You need to go around this hill further south to reach the next Crystal Offering. You may need to cut some trees to get around it at first.
Once you are on the other side of the hill, look for a small road which will take you under the pillar with the blue crystal and around the other side of the hill you just crossed. By following this path you will come to the Crystal Offering, which sits on top of a hill next to a waterfall.
Forest offers Crystal 5 places
The next Gift Crystal can be found in this area with the last two. Go back the way you came to find the fourth Crystal and go back a bit around the hill it came from. But now, instead of looking east, turn east, and go through the trees until you see a small camp you can get up to rest.
Go through the camp and continue along the path around the nearby ruins, and you'll find the Gift Crystal sitting on the the cliff behind the ruins is low.
Forest offers Crystal 6 places
You need to backtrack to the fast travel spot in the forest to find the next Crystal. From the fast travel area, head north and hug the east wall. You'll eventually reach the few stones you need, and you'll find the Gift Crystal hiding behind them under a small arch.
It's kind of a secret area like the one where the second Crystal was, so you can't find it just by walking around.
If you don't see it, look around the area where the
muddy river
start, and you should see the stone covering the entrance.
Forest offers Crystal 7 places
To find this Crystal, go to the fast travel area in the forest and follow the path north. Pass the Ancient Temple on this road and continue until you reach another temporary camp. You should be able to see the Crystal across the pond near the camp – but there is no clear road to get there.
To get the crystal, turn the pool to the other side and go to the edge of the cliff. When you get there, take an immediate left and follow the path around the cliff. This will lead you around and directly to the Crystal Gift.

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Forest offers Crystal 8 Places
The last Gift Crystal is as deep in the forest as you need cross the muddy river, which is located near the fast travel area. To cross it, make sure you reach the various ladders and planks in the river in time to avoid drowning.
Once you reach the other side, go around the pedestal where you insert the Offering Crystal and follow the right fork in the path around the various mushrooms and plants that try to attack you. Continue along the road until you reach a blue crystal at the top of the pillarthen look for a small collection of trees in the middle of this area.
If you know where to find the Ancient Temple here, the tree is behind it.
Now is the time to cut, because the The crystal is hidden between the trees. Slice as you need, and you'll soon see the sparkle of the ripe crystals. When you get the last Crystal, you can unlock the forest sanctuary and get another Luma Egg, along with many other rewards that can be hard to find there. Luma island.