It was nice but different experience. There only few such kind of places open for public. ITs proud of nation and sign of determination and decision making of govt. Its Actually one simple glimps of preparation of possible conflict during cold war era. Almost 150km away from Chongqing city, situated at the edge of Yangzi river in mountain valley. All under ground and require more or less 90 minutes to visit it completely. Entrance ticket is 65RMB. and cost me 5RMB for car parking for two hours. Inside weather is quite comfirtable and Public washrooms as well as automatic water vending machines are available. Can choose it in rainy day.