Chum Saeng Waterfall also known as “Rainbow Waterfall,” is a large waterfall located in Kraburi District, Ranong Province—one of the rainiest regions in Thailand. This abundant rainfall helps preserve the surrounding tropical rainforest, keeping it lush, green, and rich in biodiversity throughout the year. The waterfall stands approximately 60 meters high with a cliff width_ of over 20 meters, featuring a single-tier cascade where water plunges directly into a basin below, creating a powerful  and a significant amount of mist—key elements behind its unique natural phenomenon.

The highlight of this waterfall is the appearance of a “rainbow” formed when sunlight hits the fine mist at the right angle. This natural spectacle is most visible between 9:00 and 11:00 AM, especially during the rainy season from May to November when water flow is at its peak. The sight of a vibrant rainbow arching across a massive curtain of falling water creates a rare and mesmerizing scene not commonly found in typical waterfalls.

During the rainy season, the waterfall becomes particularly dramatic, with heavy streams of water covering the entire cliff face and the sound of rushing water echoing through the forest. The surrounding area is often filled with a light mist and high humidity, allowing plant life such as large trees, ferns, mosses, and ground vegetation to thrive, showcasing the richness of a true tropical rainforest ecosystem.

In contrast, the dry season from December to April sees a noticeable reduction in water volume. The flow becomes gentler, making it safer for visitors to enjoy the natural pool at the base of the waterfall. Although the chances of seeing a rainbow decrease, accessibility improves as trails become less slippery, making it ideal for relaxation and nature picnics.

Reaching Chum Saeng Waterfall requires a bit of effort. From Phetkasem Road around kilometer markers 529–530, visitors must turn onto a dirt road and continue for about 3 kilometers to a parking area. From there, a short walk along a natural trail—often damp and lined with tree roots—leads to the waterfall. Proper footwear with good grip is highly recommended, especially during or after rainfall.

As the site remains largely undeveloped and free from commercial tourism infrastructure, Chum Saeng Waterfall retains its raw, untouched charm. There are minimal facilities, making it an ideal destination for nature lovers, photographers, and those seeking peace and solitude. It stands as a true hidden gem, where the harmony of landscape, climate, and ecosystem comes together to create a uniquely beautiful and tranquil natural escape.

• Recommended time: May – November (best water flow and most scenic)

• Best time to see the rainbow:  9:00 – 11:00 AM

• Preparation: Wear non-slip shoes and bring insect repellent

• Caution: Trails can be slippery, especially during the rainy season

Admission Fee:

• Free of charge

Opening Hours:

• Open daily from 08:30 AM – 04:30 PM