Yoshinogari-Iseki (Yoshinogari- Ancient Ruins) is located in Saga prefecture and is a large scale village mainly prospered during Yayoi period that is dated B.C. 300 to A.D. 300. Yayoi period is generally though as a period when rice cultivation was introduced from Korea and China. It is said that there were large scale inflow of people from Korean Peninsula and China who are called Toraijin, a Japanese word means people from other countries. Traijin allegedly brought about some innovative technologies into Japan in that era.
This kind of structure is widely seen all over the world, and many of those have a device to prevent mice or rats from invading into them. That device is also seen in above picture; there are flat boards on top of the each pillars. As to the purpose of these structure, however, there has been an argument where some are holding that they should be used as houses. Some people says they had been used as residences for noble people who would like to avoid humidity in paddy field are.
One of the architectural features of the houses in Yayoi period is their raised-floor style. That was a device for preventing rice to be eaten by mice or rats. Therefore, warehouses particularly was built in that style. Keeping good ventilation also is a purpose of that style. Preventing rice from becoming moldy was also important for people living in that period. In fact, raised-floor-style house is mainly seen in southeast Asia where there is a climatic feature of high temperature and high humidity.
Raised-floor-style warehouse of Yayoi period