Khun Dan Prakarnchon Dam initiated by His Majesty the King is located at Ban Tha Dan, Hin Tang Subdistrict, Mueang District, Nakhon Nayok Province.  The Dam was built in accordance with H.M. the King’s initiative, so as to mitigate the hardship of people in Nakhon Nayok Province and vicinity.

Dam comprises a main dam and a secondary dam.  It is the largest and longest roller compacted concrete (RCC) dam in the world with the total length of 2,720 meters and the height of 93 meters.  It receives water flowing from Khao Yai National Park through Heo Narok Waterfall to the reservoir with the storage capacity of 224 million cubic meters.

Benefit   Water for agriculture, domestic consumption, solution of acid soil, being fish breeding ground and flood alleviation, being a new tourist attraction of Nakhon Nayok.  Tourists are able to appreciate Khao Yai National Park from the dam crest, to enjoy the spectacular scenery in front of the Dam and observe the landscape of Nakhon Nayok Province behind the Dam.

Value  Khun Dan Prakarnchon Dam is initiated by His Majesty the King; therefore, it is one construction structure representing the royal benevolence to Nakhon Nayok people and Thai populace.

Kaeng Thiam (artificial islet) Project for tourism and sport and only one international canoe slalom course in this region, generates tourism activities and increases an income to the tourism entrepreneurs of Nakhon Nayok Province.