Written records of the history of China can be found from as early as 1500 BC under the Shang dynasty (c. 1600–1046 BC). Ancient historical texts such as the Records of the Grand Historian (ca. 100 BC) and the Bamboo Annals describe a Xia dynasty (c. 2070–1600 BC), which had no system of writing on a durable medium, before the Shang. The Yellow River is said to be the cradle of Chinese civilization, although cultures originated at various regional centers along both the Yellow River and the Yangtze River valleys millennia ago in the Neolithic era. With thousands of years of continuous history, China is one of the world's oldest civilizations, and is regarded as one of the cradles of civilization.