Samurai residences and merchant houses stand in the same row. Ōmori grew at the foot of the Iwami Ginzan silver mine, strung along a single road in a narrow valley, and the two kinds of house are mixed along it rather than separated into quarters. A castle town divided its ground by rank. A mining town gathered people wherever the work was, on whatever land the valley allowed, and the usual explanation is simply that there was no room to sort anybody.

Ōmori Ginzan was designated an Important Preservation District in December 1987. Follow the road inland and it takes you to the mabu, the mouths of the old shafts, so the streetscape and the workings can be walked as one continuous route. Ōta's town centre is about twenty minutes away by car, and there are shops and workshops in the village run by people who came from elsewhere, so the population continues to turn over. Inside a mabu the air stays cold in summer and the cut is barely wider than one person, which conveys the scale of the operation better than any figure.

Mining is an industry that ends when the deposit does. What kept a town here afterwards was the infrastructure around the silver rather than the silver: the road out and the port at the other end of it. When the digging stopped, the function of being a route remained, and the road went on carrying things that had nothing to do with ore. Ōmori survives as a settlement because it was a mining town without ever being only a mining town, and the mixed row of houses along its one street is the earliest evidence of that, laid down before anyone knew it would matter.