The "In the Mountains" World Quest in Genshin Impact requires the player to thaw out all the shards from the strange ice in Dragonspine. Doing so grants you access to the Peak of Vindagnyr domain at the top of the mountain, and unlocks the "Skyfrost Nail" achievement. Read on to learn how to progress through the Dragonspine area and complete this quest.
Talk to Iris in the Dragonspine Adventurer Camp to begin the quest. She'll ask you to investigate some strange ice in the mountains. Head to the location indicated by the quest on your map.
Genshin Impact Dragonspine: How to Thaw All the Shards Out
Once you're there, you'll find a block of blue ice that can't be melted with fire in the typical manner. To break it, you'll have to attack a Scarlet Quartz, a bright red crystal found throughout Dragonspine. Breaking the Scarlet Quartz drops a crystal that you can pick up. After picking up the crystal, your character will be infused with energy that allows you to break the strange ice by attacking it.
You'll have to break four Scarlet Quartzes around the area in total to thaw out the ice, one of which is located behind a Frostarm Lawachurl. After breaking the strange ice, activate the orb to unlock the Frostbearing Tree. The shard you thawed out will fly up to the summit of the mountain.
There are two more shards that you have to thaw out. The first is located in the Entombed City - Outskirts.
Upon arriving, you'll see five Cryo totems and a Warming Seelie. Activate the device and watch the Warming Seelie go to the five totems; then, use a Cryo character to activate the five totems in the same order. You'll be rewarded with a Precious Chest containing a Crimson Agate. Once you open the chest, the Ruin Guards near the area will come to life. You'll have to defeat two Ruin Guards, and then a Ruin Grader.
After completing the fight, glide down into the cavern below. Here you'll find the second shard, and like before, you'll have to use four Scarlet Quartzes to break it. Three will be available for you. To unlock the final Scarlet Quartz, guide the two Warming Seelie to their gardens. The first is floating above the strange ice; the second is trapped in a mound of ice near the stele with Ancient Carvings, which you'll need to melt with Pyro.
After thawing the ice, activate the orb, and the two Ruin Graders in the room will activate and attack. However, they're much weaker than the previous enemies, so you can quickly defeat them and move on.
The second shard is located in the Starglow Cavern. You can enter the cavern from the waypoint as shown.
Descend into the cavern, and you'll find that the strange ice is blocked by a barrier. Complete the challenge in the room to remove the barrier. The challenge is quite tricky to complete, because Cryo enemies will spawn around the room while there is water in the middle, making it easy to get frozen. The first three waves consist of hilichurls, while the last wave consists of three Cryo Abyss Mages. Icicles will also continually fall from the ceiling during the challenge. It's a good idea to guide all the Warming Seelie in the cavern to their gardens before beginning the challenge, so you have a source of warmth.
After completing the challenge, thaw out the ice as you did before, using the four Scarlet Quartzes found around the cavern.
For the final step, head to the summit of Dragonspine.
You'll have to thaw out all three shards from the ice again, except this time, they are suspended in the air. Having an archer is handy here, as you can break the Scarlet Quartzes and then shoot the ice shards without having to climb up to them.
The first Scarlet Quartz is near an inactive Ruin Guard close to the teleport waypoint. After you break the first shard, head up the slope until you find a Frostarm Lawachurl. Defeat it, and you'll find the second Scarlet Quartz. Then, after breaking the second shard, follow the Warming Seelie up to an Anemo Totem. You'll need to use an Anemo character to activate it, generating a wind current. Glide up the wind current and through the accelerating rings to reach a hilichurl camp; there, you'll find the third Scarlet Quartz.
After thawing out all three shards, glide down to activate all the orbs revealed by the broken shards. You'll be rewarded with a Luxurious Chest, and unlock the Peak of Vindagnyr domain. Don't forget to also claim the three Precious Chests and one Exquisite Chest near the entrance of the domain.
Finally, report back to Iris to end the quest. She'll give you 60 Primogems, along with several other items, as your final quest reward.