Oudong is a former town located in the Phsar Daek Commune of Cambodia's Kampong Speu Province. It is situated at the foothills of Phnom Oudong, also known as Phnom Preah Reach Troap, approximately 35 km northwest of Phnom Penh along National Road No. 5.
The site served as a royal residence and the capital of Cambodia for nearly 250 years during the post-Angkorian period between 1618 and 1866. It is most notable for its monumental royal necropolis, which features the tombs of sovereigns from several centuries scattered across the prominent bisected mountain.