In April 1566, Imagawa Ujisada issued a vermillion-sealed decree to Fuji Nobunada, high priest of Fuji Sengen Shrine, designating the Ōmiya market (held six times monthly) as a free market. This stabilized the market and protected merchant traffic through duty exemption.
The coordinate represents the Ōmiya area around Fujisan Sengen Taisha (Miyamachi, Fujinomiya City).
Certainty: HighHow far the account above is supported by the cited sources. It does not refer to the precision of the coordinates or the dating.
See it on the 1566 map