This was a stop for people driving along the road. Then the highway was built and the whole thing appears to have gone out of business. The place is called "Yoroi" and features a painting of Mt. Fuji. The rest is lost to weeds. Upon entering, I found a giant empty space that had once been used as a cafeteria. In the center of it all was a single black hat sitting suspiciously on the floor. There were signs of squatters everywhere so I didn't feel comfortable walking in much further.
Off to the left of the building was a bathroom that had fallen to pieces and a shed containing a collection of fire extinguishers.
