Samut Prakan Province, Samut Prakan, or Samutprakarn, is one of the central states of Thailand, established by the Act Establishing Changwat Samut Prakan, Changwat Nonthaburi, Changwat Samut Sakhon and Changwat Nakhon Nayok, Buddhist Era 2489, which came into force May 9, 1946.