Chiang Saen is an important entrepôt for Thailand's trade with other countries on the upper part of Mekong River.

[1] According to an ancient chronicle,[2] the original city of Chiang Saen (Chiang: 'offshoot', saen: '100,000') was built in 545 CE in an area called Yonok by Tai migrants from the Chinese province of Yunnan, and was an important city (Southeast Asia Mandala-model mueang) of the Lanna ('million paddies') Kingdom.

[4]: 226 The city was sacked by Chao Kawila of Chiangmai during the reign of Rama I, because it had been the Burmese base of operations in the preceding years.

The 1,328 m high Doi Luang Pae Mueang massif (ดอยหลวงแปเมือง) of the Phi Pan Nam Range rises at the eastern end of the district.

Chiang Saen is to be the site of the Trin Nakara Golden Triangle, a 40 billion baht mixed-used project built by the Innovation Group Co Ltd.

[9] The site will include zones for luxury holiday facilities, and with what Trin calls a world-class health centre, condominiums, a premium shopping complex, souvenir shops, an international convention centre and community and local product OTOP stores.