Archaeologists have identified the dilapidated walls in northeast China to be the remains of the "Wooden" Great Wall, breaking the stereotype that the landmark wall of China was only made of stone and earthen bricks. Some willow fences, found in the mountainous areas of Dandong City, Liaoning Province, helped corroborate the existence of the "Wooden Great Wall", which is mentioned in ancient history books, according to a report jointly released by Liaoning Culture Relics Bureau and Liaoning Bureau of Surveying and Mapping. The willow fences were built upon the remains of the oak walls in the Qing Dynasty (A.D. 1636 - 1911), after the wooden structures corroded and collapsed, said the report. Historical records attributed the oak walls to the Ming Dynasty (A.D. 1368 - 1644), when defensive walls were rebuilt from stone, earth, and wood in some parts. The Great Wall was originally built in the Warring States Period (475 B.C. - 206 B.C.) to defend China against northern nomadic tribes. But most of the standing walls, which extend nearly 9,000-km in north China, were rebuilt in later dynasties, including Ming.