Chet Si Waterfall is located in Ban Don Siat, Tambon Ban Tong, Amphoe Seka. This very beautiful waterfall, especially during the rainy season, originates from a stream of Huai Ka-am and flows along a high sandstone cliff to spread over a long line. The falling water that hits the rocks below causes a spray of water which gives rainbow colours when seen in sunlight. So came the name “Namtok Chet Si,” which means a waterfall of seven colours.