The Om Tuk Festival (also called Bon Om Touk or the Cambodian Water Festival) is one of Cambodia’s biggest and most joyful national celebrations. It usually takes place in November, marking the reversal of the Tonlé Sap River’s flow — a natural phenomenon unique to Cambodia — and celebrating the end of the rainy season and the beginning of the harvest season. Main Activities • Boat races: Long, colorful boats with up to 80 rowers compete on the Tonlé Sap River in Phnom Penh and other provinces.