To use the elevator, Telas will require 25 iron ore.
You can get iron ores from mining Iron nodes (20 mining level).
Now you have access to the elevator.
In this dungeon, you can find a Worker Golem spawn.
If you pass through the room with the Worker Golem, you will find a staircase downwards
On the lower floor, a mini-quest awaits you. Along the way, you will encounter War Golems, which are significantly stronger than Worker Golems. Recommended level is 80+ or 60+ in a party.
At the end of the path, you will find a quest chest with a reward.
Also, in this instance, there is a second quest. It is located behind closed doors.
To open the doors, you will need a Teleport Crystal. It has a small chance of dropping from Worker Golems.
Once you have obtained the crystal, speak with Telas near the doors.
Behind the doors, you will encounter a large spawn of War Golems and another quest. Recommended level is 150+, preferably with a party including a tank.