Chachoengsao or Paet Riu is a province in eastern Thailand. It has a history dating back to the reign of King Borommatrailokkanat in the Ayutthaya period. People originally settled by the Bang Pakong River and along canals.
"Luangpho Phuttha Sothon" is a centre of faith of the people of Paet Riu.
In the past, Chachoengsao was a fourth-class city under the ministry of defence. In 1916, its status was changed from a city to a province