Phnom Kulen is in Svay Leu and Varin districts, about 60 kilometers from Siem Reap provincial town and 25 kilometers from Banteay Srei.
Phnom Kulen( Kulen Mountian) has major symbolic importance for Cambodia as the birthplace of the ancient Khmer Empire, for it was at Phnom Kulen that King Jayavarma II proclaimed independence from Java in 804 CE. Jayavarman II initiated the Devaraja cult of the king:99–101 a linga cult, in what is dated as 804 CE and declaring his independence from Java of whom the Khmer had been a vassalage state (whether this is actually “Java”, the Khmer chvea used to describe Champa, or “Lava” (a Lao kingdom) is debated, as well as the legend that he was earlier held as a ransom of the kingdom in Java. See Higham’s The Civilization of Angkor for more information about the debate). During the Angkorian era the relief was known as Mahendraparvata (the mountain of Great Indra). Phnom Kulen was further developed under the rule of Udayadityavarman II, who made it the capital of his empire and constructed many temples and residences as well as the 1000 Lingas at Kbal Spean. At its peak, the Kulen development was larger than modern-day Phnom Penh and one of the largest cities in the 11th-century world. It would later be eclipsed by Angkor, but still served a vital role, as its water irrigated the entire region.
This mountain plateau served as the capital of the first Khmer Empire for more than half a century before it relocated south to Hariharalaya, known today as Roluos. As many as 20 minor temples are found around the plateau, including Rorng Chen temple, the first pyramid built by an Angkorian King, but many of them are difficult to reach. Numerous important sites lie scattered across the mountaintop, which is accessible by foot or by car.