A military officer explains history of a fort barbette in Fuzhou, Fujian province, on Sept 17. The local border defense troop and a primary school co-organized the trip to Tingjiang Battery Park prior to the upcoming National Defense Education Day, which falls on Sept 19. Tingjiang Battery has been through the First Opium War (1856), the Majiang Naval Battle (1884) and the War of Resistance against Japanese Aggression (1937-1945), and is now a key historical site under state protection. [Photo/Xinhua]