Xin'an County
According to the "Old history book of Tang dynasty" (), and the "New history book of Tang dynasty" () Tuen Mun was a major trading port, and there were garrison as early as the Tang dynasty (A.D. 618–907). The geo features that described by the historical literature, matching the modern day Tuen Mun. However, some scholar also dispute the interpretation of the location of Tuen Mun. They suggests the historic Tuen Mun may refer to the Nantou in the modern day Shenzhen (historically the residual part of the Xin'an County) instead. Another scholar, Lau Chi-pang, rebutted their interpretation in his article.