Phnom Kulen, also romanized as (Phnom Koulen, Phnum Kulén or Koulen Mountain) (Khmer: ភ្នំគូលេន, meaning "Mountain of Lychees") is a mountain range in Siem Reap Province, Cambodia.
Rather than a hill range, Phnom Kulen is an isolated chain of small mountain plateaux of moderate height lying south of the Dângrêk Mountains. The range stretches for about 40 km in a WNW - ESE direction and is located some 48 km north of Siem Reap.
Its highest point is 487 m and its height is quite regular, averaging 400 m all along the range. Geologically Phnom Kulen is formed of sandstone. It was important as a quarry in Angkorian times, the major quarries being located in the southeastern angle of the massif.
There is a sanctuary in the area, Phnom Kulen National Park, straddling the districts of Svay Len and Va Rin. Its purpose is recreational and scientific in order to preserve the natural scenic features of Phnom Kulen mountain, like some famous waterfalls. The park is located about 48 km to the north of the provincial town of Siem Reap.
The Phnom Kulen mountain range is located 30 km northwards from Angkor Wat. Its name means "mountain of the lychees". There is a sacred hilltop site on top of the range. Phnom Kulen is considered a holy mountain in Cambodia, of special religious significance to Hindus and Buddhists who come to the mountain in pilgrimage.
Chup Preah is a stream flowing into the mountain’s valley. Ku Len Mountain has two waterfalls. The first is between four and five metres high with a diameter of 20 to 25 metres. The second waterfall is 15 to 20 metres high and has a diameter of 10 to 15 metres. These sizes apply to the dry and rainy seasons.
Preah Ang Thom houses a large statue of Buddha. It was built in the 16th century and is eight metres high. Preah Ang Thom is the sacred and worshipping god for Ku Len Mountain. There are also two large Cham Pa trees nearby. Besides Preah Ang Thom, Chhok Ruot, footprints of Preah Bat Choan Tuk, Peung Chhok, Peung Ey So and Peung Ey Sey, can also be seen.