The ceremonies (ngan) at Prasat Phanom Rung can be split up in two groups: The traditional ones and the modern ones.
The main traditional ngan took place every year at full moon in the 5th lunar month, April, when the locals ascended the mountain from all nearby villages and districts to perform Hinayana Buddhist rites followed by musical shows (mawlam) and dance. The participants were the local ethnic Khmer and Lao farmers and this traditional festival is still the one the elder people remember with most reverence.