One of three temple-mountains built by Yasovarman I in the late 9th or early 10th century, this peaceful but remote location (about 25km from Siem Reap) sees few visitors. The small temple is in reasonable shape, but it is the views of Phnom Kulen to the north and the plains of Angkor to the south from this 212m hill that make it worth the trip.
The remains of a 5m linga are visible at the opposite end of the hill, and it’s believed there were similar linga at Phnom Bakheng and Phnom Krom.
There is a long, winding trail snaking up the hill at Phnom Bok, which takes about 20 minutes to climb, plus a faster cement staircase, but the latter is fairly exposed. Avoid the heat in the middle of the day and carry plenty of water, which can be purchased locally.
Phnom Bok is clearly visible from the road to Banteay Srei. It is accessed by continuing east on the road to Banteay Samré for another 6km. It is possible to loop back to Siem Reap via the temples of Roluos by heading south instead of west on the return journey, and gain some rewarding glimpses of the countryside. Unfortunately, it is not a sensible place for sunrise or sunset, as it would require a long journey in the dark.