It's OK. It's beautiful. It's a little boring. You have to come back and have a look.
A pleasant trip, good environment, good service, everyone is very satisfied!
Once civil air defense works, convenient transportation, you can go to see
I learned about the predecessor of the underground city of Lower Beijing. Its predecessor was a huge underground civil air defense work, which was built in 1969 and completed in 1979. It was mainly excavated by the local people of Beijing through voluntary labor. It's a good place.
Beijing Underground City was built in 1969 as a civil air defence fortification. The underground city project, which lasted ten years, was completed in 1979. It is divided into three defensive fortification districts and leads to all directions of the urban area, forming a preliminary scale of civil air defense tunnel network.