Situated about 50 kilometers north of Siem Reap, Phnom Kulen is the most sacred mountain in Cambodia. It is widely regarded as the birthplace of the ancient Khmer empire. It is the place where Jayavarman II declared independence and founded the Khmer Kingdom in 802 AD. Thus it is considered the first capital of Cambodia before it was moved to Roluos. Visitors take a 45-minute drive ascending the mountain through a lush jungle to the plateau on the mountain peak.

There is an active Buddhist temple, a river and a waterfall on this mountain. The revered temple houses a large reclining Buddha statue carved on a big boulder. Similar to Kbal Spean, the river has carved religious emblems on its riverbed. Nearby is a large waterfall with a dotting bathing areas. Plenty of remnants of ancient Angkorian temples are visible along the path to the waterfall. The mountain is both a significant pilgrimage site and a popular picnic spot among natives here. Since this is a holy site of the locals, shoes and headwear should be taken off before entering the religious sanctuaries.

Currently, admission fee of 20 USD is required to enter Phnom Kulen.