The Dune of Magma is a location inside the Sumeru Desert, a new area brought by Update 3.1 of Genshin Impact.
How to Unlock the Dune of Magma Hidden Teleport Waypoint in Genshin Impact
Before you can unlock the Hidden Waypoints, you first will need to go to Aaru Village and talk to Bonifaz, located at the entrance and past the Statue of the Seven. This will unlock the Golden Slumber quest line.
Exploring the Dune
After you’re finished with the quest line, get to the Dune of Magma and enter it. You’ll stop at the first chamber in front of the gold impressive door and take the right path, interacting with the panel to turn off the energy-door.
Go upstairs and then left. You’ll come into a sandy room with a square-shaped hole and a Primal Ember. Release it, prompting it to go down to another pillar similar to the one we just released it from. Walk over to the square and see if the fan that lays below is active or not. You’ll need to wait for it to stop fanning and drop down, then move to the next Primal Sconce where the (if it hasn’t, wait) Primal Embler settled in.
Release it again and guide it until it phases through an energy wall. You’ll have to go to the fan and glide up, making it all the way back to the first room you got into. The Ember will be there floating: get close to it and it’ll activate one of the huge torches, opening the central door of the room. Quickly go to the right and turn off the energy wall, but don’t proceed.
Central door
Get in there. A pyramidal PrimalEmber will be waiting. Pass by it and glide down the hole in front of you. There will be a shining square panel you’ll have to step on and wait for it to activate: a VerityCell will appear. Interact with it.
Around the room you will find Pyro Torches, so switch to your Pyro user and attack them. After you light all the torches, collect the Chest in the center of the room and walk in the direction the chest is facing (towards the giant roots).
You’ll be gliding down a long way. Once you hit floor, go through the tunnel opposite of the giant roots and follow the path. There will be items and enemies on the way, but you can ignore them. At the end of the tunnel you should be able to see the Teleport Waypoint far away from you, in an area reachable via gliding.
Second Teleport Waypoint
From the previous Teleport Waypoint you should be able to see an entrance to a sort of temple. Go in that direction and upstairs. You’ll know it’s the right one because the first thing you see once you enter is a huge statue.
From this room, go to the stairs of the right and follow the path, taking stairs up again once you see them. You’ll end up in a huge empty room with the second Teleport Waypoint.