Phnom Kulen National Park, National park in Siem Reap Province, Cambodia

Phnom Kulen National Park covers 373.76 km² of the Phnom Kulen massif in Svay Leu District, about 48 km from Siem Reap. Two waterfalls, one 4–5 m tall and 25 m wide in the rainy season and another 15–20 m tall and 15 m wide, cut through the forest. The park also holds the Kbal Spean riverbed carvings and the Terrace of Sdach Kamlung.

During the Khmer Empire the massif was called Mahendraparvata, the mountain of Great Indra. There King Jayavarman II had himself declared chakravartin, King of Kings, an act considered the foundation of the empire. French scholars first noted the site's importance: Philippe Stern visited in 1936 and described Rong Chen as the first temple-mountain. In June 2013 a Lidar survey mapped the ancient city of Mahendraparvata on the slopes and revealed 30 previously unidentified temples.

The riverbed carvings at Kbal Spean show more than 1,000 lingas created during the height of Khmer art. Walking past these stone-cut symbols, you can sense how sacred the water itself was believed to be in the ancient world.

The dry season from November through April offers the best visiting conditions with easier trails and passable mountain roads. Most visitors reach the area through guided tours arranged from Siem Reap, which handle the journey to remote sites.

The mountain streams flow across ancient carved stone blocks that naturally filter water before it nourishes the plains where Angkor's temples stand. This hidden link between the upland sanctuary and the famed temple complex reveals an ingenious system of water management.