Do your best to help Rya retrieve the lost necklace, and she will escort you to Volcano Manor.
Volcano Manor is like a gothic killer's home. It's your job to complete the kill mission and come out alive. To enter Volcano Manor, you need to help a lady named Rya retrieve her lost necklace. Rya is an NPC from Liurnia of the Lakes. The Lost Necklace is a hidden quest. Only after completing the mission will Rya help you reach Volcano Manor. There are 2 clues to retrieving the necklace. You can buy that necklace for 1,000 runes, or you can kill the robber to get the necklace back.
How to enter Volcano Manor
Volcano Manor can be reached in three different ways. Players can choose according to their situation.
Path 1: Help Rya (by comparison, the easiest way)
Once you get the necklace back, find Rya, talk to her, hold her hand, and she will teleport you to Volcano Manor.
Path 2: Teleported by the enemy
This is the hardest of the three methods to accomplish. Note that you will need to fight Abductor Virgins if you decide to go this route. You must be killed by a specific attack where it traps you in its iron maiden-like body. Use the Sacrificial Twig or Twiggy Cracked Tear effect to prevent you from losing runes while teleporting. Doing this successfully will take you to the Volcano Manor underground cave.
Then go through the hermit village and keep going until you finally reach the manor. If you're having trouble defeating any of the bosses, feel free to run past them and come back when you're ready.
Path 3: Walk. Instead of the above two ways, you can also choose to walk to the manor. First, Pass the Ruin Cliff or the Grand Lift of Dectus to the Erdtree in Altus Plateau. Then head north over a bridge called Bridge of Iniquity. Then find a ladder to the ground and arrive at Ninth Mt. Gelmir Campsite (Grace). Here you will meet the final boss. Players who beat the boss or just ran over can jump off the platform to reach the Volcano Manor.
The entrance to Volcano Manor is a large interior where you can interact with many NPCs. When you enter, you first talk to Tanith, the woman sitting in the chair to the right of the fireplace. Talk to Tanith and agree to be a part of Volcano Manor. She gave you the living room key, which allows you to open other doors in the manor. Volcano Manor doesn't affect the ending of Elden Ring. You can kill all enemies in front of you, take the loot, and leave.