[2] The Jōmon site is located on the southwest terrace near the Yoshino River, and is limited to an area of 100 x 100 meters.

The distinctive feature of the pottery from this site is the extensive use of conch shells to apply patterns.

The concave lines on the surface of the pottery are also created using snail shells, rather than using a rod-shaped or spatula-shaped tool.

Period I consists of two post-hole buildings built east and west, one of which is 2 x 6 bays or more and had eaves on the north side.

There are three post-hole buildings built north and south, one east and west, three rows of fences, and a stone ditch, and with the remnants of a garden.

[2] Although there are records of visits to Yoshino by Emperor Ojin and Emperor Yuryaku in the Nihon Shoki, it is not until the entry on the construction of Yoshino Palace in the second year of the reign of Empress Saimei (656) that it can be said with certainty that a detached palace existed.