Tracing the exhibition hall deep in the green forest

#November Destinations 2025 Project 6501: "The Underground Great Wall in the Dense Forest at the Border of Hunan, Hubei, and Jiangxi Provinces" Project 6501 originated from the backdrop of the Sino-Soviet split. Construction began in 1965 and lasted for eight years in extremely secretive conditions. It was suddenly abandoned in early 1973, and its specific function, purpose, and reasons for abandonment remain unknown. It is currently the largest known man-made military-purpose cave in China. Project 6501 consists of three levels: upper, middle, and lower. Inside, there are 18 circular cement platforms, originally housing 18 large oil tanks. Project 6501 is hailed as the "Underground Great Wall of China."