Phanat Nikhom is a district in the northern part of Chonburi province, eastern Thailand. Phanat Nikhom is an ancient city dating back to Dvaravati period, called Mueang Phra Rot. Archaeologists found a fortress and city walls within the district area. In the Rattanakosin era, King Nangklao, Rama III established city, called Mueang Phanat Nikhom in 1828. It was changed to be a district of Mueang Chon Buri by King Chulalongkorn, Rama V in 1904. Phanat Nikhom was divided into new five districts: Phan Thong, Nong Yai, Bo Thong, Ko Chan and Nong Irun, Nong Chak, Nong Bon Daeng sub-district in Ban Bueng.