Death Mountain West Tunnel is west of the Death Mountain Chasm, northwest of Sitsum Shrine.
Cave Location
Death Mountain West Tunnel is located at 2239, 2682, 0522, which is west of the Death Mountain Chasm, northwest of Sitsum Shrine.
Cave Features
The cave is hot, so you will need to wear Flamebreaker armor or use Fireproof Elixir. If you are using a wooden weapon, bow, or shield, be sure to unequip them so they won't catch fire.
There is a pit full of magma in the cave, and a broken mine cart rail over it. Mine carts won't be able to make it across, so just jump across the gap. There you will find Mota, who is stuck in the cave. Talking to him will start the quest The Abandoned Laborer.
Break the wall of broken boulders east of Mota to find an area with numerous Zonai Devices, including rockets. There is also a chest buried in the dirt in this area. It contains a Cobble Crusher.
Before you use the Zonai Devices, you can go northwest through the opening in the wall to find this cave's Bubbulfrog.
As explained on The Abandoned Laborer, you can use a rocket to help Mota get out of the cave.