Cao Bang, Jan. 24 -- Phuc Sen village in the northern province of Cao Bang is not a place first-time visitors might want to stay long, as the noise may come as a shock.

That noise is the sound of thousands of knives, of all shapes and sizes, being made each year by about 350 blacksmiths of the Nung ethnic minority .

During the day the village is filled with the sounds of workers beating and hammering steel as they forge knives using traditional techniques and recycled materials.

"We have been doing this job since my grandparents' time, and I don't remember exactly when it started," said 58-year-old Long Anh Chien.

"We get steel from the shock absorbers of used cars to make the knives," he added.

Legend has it that the craft was first...