Nakhon Nayok (Thai นครนายก) is one of the central provinces (changwat) of Thailand.

The northern part of the province is located in the Dong Phaya Yen mountain range, with the highest elevation the 1292 meter high Yod Khao Kiew. Most of that area is covered by the Khao Yai National Park. The central part of the province however is a rather flat river plain formed by the Nakhon Nayok River. The southern part of the province has relatively unfertile acidic soil.

The main river of the province is the Nakhon Nayok River. It joins the Prachinburi River at Pak Nam Yothaka in Amphoe Ban Sang, Prachinburi province, which then becomes the Bang Pa Kong River.

The city of Nakhon Nayok dates back to the Dvaravati kingdom, probably founded in the 11th century. The name Nakhon Nayok was assigned to it in 1350, when it became a garrison town of the Ayutthaya kingdom protecting the eastern boundary.

January 1st, 1943 the government downgraded Nakhon Nayok Province and combined it with Prachinburi Province, except Ban Na district which became part of Saraburi Province. On May 9th 1946 the province was re-established.

The provincial seal shows an elephant holding an ear of rice with its trunk. This symbolizes the fertile rice fields as well as the forests with numerous elephants. In the background two piles of straw, trees and clouds symbolize the natural beauty of the province.

Provincial flower and tree is the Silk-Cotton Tree (Cochlospermum religiosum).

The province is subdivided into 4 districts (Amphoe). The districts are further subdivided into 41 communes (tambon) and 403 villages (muban).

Wangtakrai National Park. Is located at Tambol Hintang. The Wangtakrai waterfall is the famous traveling place of Nakhon Nayok province. It is also a famous place for botany education in Thailand.

Nangrong Waterfall. Is was located in Tambol Hintang, Khao Yai National park. It is a medium size waterfall, but it is one of the most beautiful waterfalls in Nakhon Nayok.

Sarika Waterfall. Is located in Tambol Sarika, Khao Yai National park. It is a big waterfall with nine levels. It is more beautiful in rainy season.

Lanrak Waterfall or TradHingong waterfall. Is located in Tambol Bramhmanee. This water fall is different from others. Because of its origin, many small streams created this waterfall by uniting into one stream at the stone field. The traveler should visit here between September till November.

Muang Boran Dong Lakorn. Is located at Tambol Donglakorn. First it was called “Muang Lablae”. This place used to be place of ancient town in Tarawadee and Khmer time.

Extracted from Wikipedia: Nakhon Nayok Province