Nakhon Sawan (Thai นครสวรรค์) is one of the provinces (changwat) of Thailand. The name Nakhon Sawan means Heavenly City.

The Ping and Yom rivers merge near the city of Nakhon Sawan to form the Chao Phraya River. The Mae Wong National Park on the border with Khamphaengphet province was created in 1987 to preserve the Mae Wong-Mae Pern jungle.

Bueng Boraphet is the largest freshwater swamp in Thailand, in total covering 212 km². The swamp is located directly east of the town Nakhon Sawan and extends into the districts Tha Tako and Chum Saeng. During the winter months many waterfowls migrate there. Parts of the swamp are protected as a non-hunting area.

Nakhon Sawan was a city since Dvaravati era. While part of the Sukhothai kingdom, it was called Mueang Phra Bang, the southern frontier city of Sukhothai. Later within the Ayutthaya kingdom it was an important trade center because of its location at the two major rivers from the north. It also was the common meeting point of Burmese troops before moving to attack Ayutthaya. In the reign of King Taksin the Great, Phra Bang became a Siamese military base to prevent further Burmese attacks.

When King Mongkut signed the Bowring treaty with Britain the glorious time of Nakhon Sawan began, as it became the main rice and teak trading center. However the opening of the Northern railway in 1922, the economic crisis before 1932 revolution, and finally the opening of Dejativongse bridge and Phahonyothin highway in 1950 each decreased the importance of water transportation and thus made Nakhon Sawan less important.

When in 1895 King Chulalongkorn established the monthon as part of the thesaphiban administrative reform, Nakhon Sawan became capital city of Monthon Nakhon Sawan.

The provincial seal shows a Wiman, a mythological castle located in heaven. This relates to the name of the province which translates to Heavenly City.
The provincial tree as well as the flower is Lagerstroemia loudonii (Loudon's crape myrtle).

The province is subdivided in 13 districts (Amphoe) and 2 minor districts (King Amphoe). These are further subdivided into 130 communes (tambon) and 1328 villages (muban).

Extracted from Wikipedia: Nakhon Sawan Province