The Lost Treasure is a Favor in God of War: Ragnarok that you can start by speaking with the Elder Wayfarer Spirit on Dragon Beach in Svartalfheim. To access Dragon Beach, however, you must have acquired the Draupnir Spear by completing Forging Destiny. You also visit the area during Favor: Spirit of Rebellion.
After getting to the bridge on Dragon Beach, speak with the Elder Wayfarer Spirit to start the Favor. Once you have accepted that, enter the cave on the left of the statue. Clear the enemies and use a Fire Bomb to destroy the debris. Continue to delve deeper into the cave while clearing debris to come across a mini-boss named Ormstunga.
While not terribly tough, Ormstunga can be a pain because of how agile he is. Our best advice is not to over-commit — just land a couple of hits and back away. He has an unblockable leap attack which requires you to be pretty quick when it comes to dodging it. Aside from that, he will sometimes spit venom on the ground which is not too hard to avoid. Other than that, you can easily block or parry most of his attacks.
Before pushing forward, make sure to collect a Yggdrasil Rift and a Legendary Chest behind some debris. There will also be a Treasure Map on the right side.
From there, you will need to head north to Alberich Island. After defeating some enemies, collect the Nornir Chest if you want. There is also a Berserker Gravestone here but you do not have to do it right now if you are not confident enough.
Once you are done, climb up using the Draupnir Spear to speak with the Wayfarer Spirit. From there, destroy the soundstone on the left using a Sonic Arrow. Go ahead and destroy a rock in the distance using the Draupnir Spear to pull the grappling point upward. From there, swing to the other side for a Yggdrasil Rift and a Treasure Map on the right side.
There will be another rock that you can destroy with the Draupnir Spear. Once done, pull the chain and freeze the cog in the distance. Now swing across the other side, freeze the geyser, and take the lift. After defeating the enemies, continue to climb up until you get to a Legendary Chest.
Lastly, return to the Elder Wayfarer Spirit to complete The Lost Treasure.
You will get 3,000 XP for Kratos, 750 XP for Freya, Svefnthorn, Jewel of Yggdrasil, and 5,000 Hacksilver.
There are a few more Favors that you can complete in Svartalfheim:
This is all we have got on how to complete The Lost Treasure in God of War: Ragnarok. For more tips and strategies, feel free to check our God of War: Ragnarok wiki page.