At merely 487m, Kulen Mountain (Phnom Kulen) is nothing impressive in term of height; but it is the sacred hill in the eyes of the Cambodians. There was lots of history behind this national park (pending for UNESCO World Heritage title).
The Chinese name for this hill is Lychee Mountain (荔枝山). 中国元朝使节周达观到此一游。撒下了许多荔枝种子，树多成林，便是荔枝山名称的由来。
The hill is 48km from Siem Reap town, but it took us around 2 hours to reach the top due to poor road conditions. Road builder collects USD20/person but did not maintain the mountain road well enough to attract more tourists.
The mountain (still looked like a hill to me) has 3 main attractions:
1) cascaded waterfall
2) reclining Buddha
3) River with a thousand Lingas
The waterfall is normally the last stop over for the tourist to have lunch, swim or picnic near the pool. The cascaded falls measured 5m and 20m tall, so the lower fall looked nicer.
The river stream (Chup Preah) is the source for the Siem Reap River.
If you see through the water surface, you can see many religious carving, known as the Linga and Yoni (sexual organs). So this place was called “River of one Thousand Lingas”. The ‘penises’ purify the water flowing through them. According to the ancient belief, the carvings of the sexual organs represented fertility, which has the symbolic importance as the birthplace of the Khmer Empire.
The rocks used to build Angkor Wat was carved and transported using this river (30km away). This is the reason I started my Siem Reap travel post with Phnom Kulen instead of Angkor Wat. King Jayavarma II declared independence from Java in year 802 (or 804 according to different guide books).
On the bigger river rock, one could find the carving of the Hindu God Vishnu, with his wife Lakshmi and the serpent.
Preah Ang Thom Temple sits on top of the rocky hill top, with a 9m long reclining (or sleeping) Buddha.
It was carved straight from this rock, and housed by the temple.
After visiting Angkor Wat, one could start to appreciate how incredible was the engineering and logistics feat to transport the gigantic rocks from this rocky hill to Angkor Wat.
If you do not have time, my advice is skip this site. There are not many impressive attractions on the hill except for its significance in Khmer’s history.