“Emerald Pool” Emerald Pool Highlights Thung Teao Forest National Park is a virgin rainforest home to spectacular flora and fauna unseen elsewhere in Thailand. A 2.7 kilometres nature trail provides a superb vantage point, plus there’s a waterfall to explore, although the major attraction is the emerald pool also known as the crystal pool. The emerald waters are wonderfully warm and crystal clear making them great for swimming in, there’s even a small ladder to help you get in and out.