Flowing to the north of Muak Lek in a far-flung corner of the Khao Yai region, Chet Sao Noi Waterfall usually gets overlooked by travellers. It's not Thailand’s tallest, widest, or most popular waterfall, but with a haunting backstory and scenery that's right out of a fantasy novel, there’s something mesmerising about Chet Sao Noi.