Chet Si Waterfall is situated within the Phu Wua Wildlife Sanctuary in Ban Tong Subdistrict, Seka District, Bueng Kan Province. The waterfall originates from the Kra-am Stream, which flows across the majestic Phu Wua mountain range. The geological landscape is characterized by vast, reddish-brown sandstone plateaus interspersed with lush mixed deciduous and dry evergreen forests. The waterfall itself is a multi-tiered natural wonder consisting of four primary levels, each offering a distinct aesthetic dictated by the erosion of the ancient rock formations and the presence of natural basins.

The defining characteristic that lends the waterfall its name is a spectacular optical phenomenon. As the water cascades down the steep cliffs, it shatters into a fine, translucent mist that fills the surrounding air. When sunlight strikes these water droplets at the correct angle, it creates a vivid, seven-colored rainbow shimmering above the water’s surface. This breathtaking sight is most prominent during the rainy season, when the water volume is at its peak, resulting in a broader "water curtain" and a more intense display of refracted light colors.

The environment surrounding Chet Si Waterfall serves as a vital ecological sanctuary, home to a diverse array of wildlife and rare plant species typical of the Isan plateau. Visitors must traverse a shaded nature trail to reach the falls, offering an immersive experience into the tranquility of the forest and the unique sandstone geology of the region. Beyond being a popular spot for swimming in cool, natural rock pools, Chet Si Waterfall is a natural heritage site that embodies the rich biological diversity of Upper Northeastern Thailand.

• From Bueng Kan city center, take Highway 212 towards Bung Khla District, then turn right onto Highway 2026 towards Seka District. Follow the signs for Phu Wua Wildlife Sanctuary and Chet Si Waterfall. The roads are generally in good condition, though cautious driving is recommended for some sloped sections

• Timing for the Rainbow: To witness the signature seven-colored rainbow, aim to be at the waterfall between 10:00 AM and 2:00 PM, when the sun hits the mist at the perfect angle for refraction.

• Visit During High Season: The most breathtaking views occur during the late rainy season (August – October). During the dry season, the water volume may decrease significantly, making the "rainbow mist" less visible.

• Wear Proper Footwear: The terrain consists of sandstone plateaus and rocky paths that can be slippery due to moss. It is highly recommended to wear hiking sandals or shoes with excellent grip.

• Strict Environmental Compliance: As this is a Wildlife Sanctuary, Styrofoam, single-use plastics, and alcohol are strictly prohibited. Always carry your trash back out to preserve the pristine nature.

• Bring Waterproof Gear: The mist at Chet Si is very fine and pervasive. Ensure you have waterproof bags for electronics and cameras, and bring a change of clothes if you plan to swim in the natural rock pools.

Admission Fees:

• Thai Nationals: Adults 20 THB, Children 10 THB

• Foreigners: Adults 200 THB, Children 100 THB

Opening Hours: