Notice how thin the strands are. This is why somen is often called Japanese vermicelli. Mrs. Igata says her somen is so thin that, when dry, five strands can fit through a pinhole.
The article [in Japanese only] about Mrs. Igata's shop states that the town of Nankan has been known throughout the region for its tasty somen since the days of the samurai—which is also when the Igatas' shop opened: Mrs. Igata and her husband are the 9th generation to run the shop since it first opened for business roughly 300 years ago.
Historical sites to see in Nankan include a restored teahouse originally built in 1852. The teahouse, shown in the picture below, served as a stop-over point for local daimyo (fuedal lords), samurai, and other big shots traveling to or from Edo (as Tokyo was called then).
The town's website also has a slideshow of local scenery.