Blacksmith's shop

Located in the caverns under the steppe, modern shop surrounded by stone.

Don't touch my shit.

Gold, gems, other weapons (very rarely), precious metals or materials.

Dragontongue, Common

Nice and cool, a constant 54 degrees Fahrenheit with an occasional breeze from the outside world.

Erosional cave with an underground stream running through it. Platforms were created to give living space and a work area. Waterwheels take advantage of the river to drive the forge.

Yama needed a place to practice his craft while away from people, so he found a cavern with plenty of space and far enough underground so that he could rarely interact with humans.

The Great Wyvern War

Based off of the Luray Cavern in Virginia, most of the surrounding walls are sedimentary rock, with many formations of crystals, stalactites and stalagmites, and a few places with standing water. Most of the water comes from the river that runs through the entire cavern, but it empties out into an underground aqueduct.

The river powers a waterwheel, and that drives the power hammer and grindstones. Most metal shavings can't be sent down the river, so they are collected, reconstituted, and given as party favors because that's all they're really good for.

Natural gas is found underneath The Forge, but there is only one vent that was made to access it. That vent is constantly checked and rechecked due to the fact that an explosion would probably kill him at best and wreck his shop at worst. To Yama, the forge is where his entire creative process can be unleashed.

While most pieces can be forged, larger pieces with overlays or bulkier parts wouldn't be feasible without some way to cut them efficiently. Yama can simply split metal without the need to cut it, though blades formed this way are likely to need extra heat treating.

Multiple racks with hammers, engraving tools, and drill bits line the walls.

Heavy equipment include:
Pneumatic power hammer
Grindstones (with multiple grits)
Gas-powered forge
Charcoal forge
Multiple quench tanks (must be cleaned out with every new piece)
Flywheel press
Multiple dies for power hammer and press
A lathe for both wood and metal (with corresponding bits)
Multiple tools for engraving, annealing, inlaying, etc.

Quench liquids:
Mineral water
Sweet oil (made from animal or seeds)
Brine (specially-mixed salt water)

Also included:
Pull-out couch for sleeping
Pantry full of snacks
Modified phonograph to play in the loud forge, can be controlled with a dial (made of aluminum so it can be moved with Earthbending).
Collection of records from all over (those guys up north with their fancy electric instruments are a real hit!)
Bass guitar he bought off a collector for "cheap," worth a softball-sized gold nugget. Needs electricity to be amplified, but there aren't any wired connections in the cavern.