伊豆国
Izu Kokubun-ji was founded in 741 as the provincial temple of Izu Province; however, the precise date of its construction has not been confirmed from archaeological materials or literature. As the project for such a large-scale civil engineering project was unprecedented for relatively poor and remote Izu Province, the financial burden on the local government was also very great, and the temple was not completed until around the Hōki era (770-780). The temple was converted at some time in the Heian period to the Shingon sect, and was burned down repeatedly in the incessant battles between the forces the Takeda clan and the Odawara Hōjō clan during the Sengoku period. In the early Edo period, it converted to the Nichiren sect and was completely rebuilt; however, these buildings were all destroyed by the 1855 Ansei Edo earthquake and the site was abandoned.