Dong Lakhon Ancient City is an almost round oval city. There is a moat and an embankment around it. It covers an area of about 3,000 rai and has a diameter of about 700-800 meters. Originally there was a two-story berm, but now only one outer layer remains. The outer embankment is higher than the inner embankment. But the inner ridge is thicker. The nature of building the city is adjacent to the original Nakhon Nayok River. which is in contact with the sea coast suitable for maritime trade and can also do farming around It is similar to the ancient city of Dvaravati in the vicinity of Thailand. It is estimated that the inhabitants were in the 12th-18th century AD and were in the ancient maritime trading network.