This small waterfall hides the beauty and charm in Khao Yai National Park, the first national park of Thailand which covering the four provinces: Saraburi, Nakhon Ratchasima, Prachin Buri, and Nakhon Nayok, 2,176,000,000 square meters in total. At Khao Yai National Park, apart from being the trekking place to enjoy the richness of the mixed forest, dry evergreen forest, tropical rain forest, montane forest, pasture land, or the forest that resulted from the shifting cultivation, it is the water source of the important rivers such as Prachin Buri River, Nakhon Nayok River, Bangpakong River, Lum Takhong River, and Pra Plueng River which finally become the habitat of wildlife animals such as barking deer, deer, elephant, tiger, gaur, chamois, gibbon, hedgehog, hyena, civet, Siamese hare, birds, and insects. Within the national park territory, there are many tourist sites which facilitate the recreation activities such as bird-watching, swimming, rafting, trekking, and climbing, especially at Than Rattana Waterfall as it is the vast valley underneath the waterfall and the flower field that is blooming during spring. However, as there is no trekking route, it is difficult to access to. The most popular activity here is rappelling from the hundreds-high cliff that consists of four floors which each floor has different height and incline. This is the activity for the adventurous tourists.