Oudong (aka Odong or Udong) is a Tonle Sap River cruise port and town in Cambodia, located in the northwestern part of Kampong Speu province. It is at the foothill of Phnom Udong mountain, approx 40 km (25 ml) northwest of country's capital city Phnom Penh, Oudong was Cambodia's capital and royal residence until 1866.
The name of the city of Oudong is derived from the Sanskrit "uttunga", meaning tall, which presumably refers to the mountain. It had gained religious significance, so it might have undergone extension toward: 'supreme' or 'great'.
Oudong was established in 1601 by King Srei Soryapor, after Longvek's abandonment. Under King Ang Duong's reign (1841-1850), he constructed terraces, canals, bridges and also erected hundreds of pagodas in the region.
During the period from 1618 to 1866 Oudong was formally named Oudong Meanchey, the home to succession of kings dethroned from the former capital city Lovek by invading Thais. In 1866 Oudong was abandoned by King Norodom in favor of Phnom Penh. In 1977 Oudong was extensively damaged by Khmer Rouge, along with the monuments, temples and religious structures there.
On September 1, 1992 the site was added to UNESCO World Heritage Tentative List, in the Cultural category.