Jiuzhai Valley’s fabled blue, green and turquoise-coloured lakes are its most famous feature. The various colours are a result of the scattering, reflection and absorption of sunlight. Suspended calcium and bicarbonate in the water, travertine deposits, seasonal changes in the vegetation surrounding the lakes and the multi-coloured algae in the water create the many colours of these crystal clear lakes. A well known Chinese saying states "once you have seen Jiuzhai Valley, there is no need to see any other water".


        Over thousands of years, rock falls, earthquakes and other natural phenomena have formed the unique landscape and colourful lakes of Jiuzhai Valley. Underground channels, flowing along joints in limestone, play a significant role in draining the higher lakes and maintaining the water level in some of the lower lakes. Although Long Lake (Chang Hai) has no river outlet some of its water seeps through the barrier moraine in front of it and into the Five Coloured Pond (Wu Cai Chi). Water is also discharged through an underground channel into the Arrow Bamboo Lake (Jian Zhu Hai) and the Five Flower Lake (Wu Hua Hai) in the adjacent Ri Ze Valley. These channels, formed by fissures and faults in the limestone, connect the two valleys.