Phnom Bok, Archaeological site and mountain in Siem Reap Province, Cambodia

Phnom Bok is a 221-metre hill in Siem Reap Province topped by Prasat Phnom Bok, a Bakheng-style temple with three identical sanctum towers in a row on a single laterite terrace. The towers open to the east and west, and two large frangipani trees grow over the ruined structures.

The temple complex was built between the 9th and 10th centuries on orders from King Yasovarman I as part of a larger religious strategy. This construction reflected a period when such religious monuments increasingly shaped both the landscape and the kingdom's power.

The three towers housed statues of the Hindu Trimurti — Brahma, Vishnu and Shiva — whose images were found at the site. The towers now stand ruined and the statues are damaged or lost, so visitors see the outer sanctuaries rather than entering intact shrines. The temple is also known for its triple sanctuary dedicated to these deities.

The hill is reached from the road to Banteay Srei; an eastbound road continues 6 km to Banteay Samré, from where 635 wide steps climb to the summit. The ascent is exposed, and the ruined towers at the top are overgrown by two large frangipani trees.

The temples are aligned in ways that mark important celestial events such as the solstice. This astronomical function was intentional, showing that the builders integrated sky cycles directly into the architecture.