On one side of the volcano, there was a crimson river, which wasn't water, but magma.
The Zhu family had drawn the magma from inside the volcano, allowing it to flow like a river.
Within the magma, there were many black solids of varying sizes, which were not stones, but metals smelted within the volcano.
The so-called Earthfire Steel was actually steel that had been smelted multiple times by the volcanic magma.
Smelting, forging, smelting again, forging again; after several rounds, the ordinary pig iron would transform into the tough and resilient Earthfire Steel.
Standing at the foot of the volcano, looking up at the entire mountain, no one could help but admire the craftsmanship of the Zhu family.
Utilizing the volcano to forge weapons, there's nowhere else like it in the world.
There might be more skilled forging masters than the Zhu family, but no power uses the volcano for mass weapon forging like they do.
