On September 4, 1839 the people looked out of these windows of Dapeng Fortress to see five British naval vessels launching a surprise attack. So Chinese troops commandeered the in fishing boats and led by General Lai Enjue they defeated the British! Ha--you don't hear that history everyday--least it was not told to me when I was in the British Marines!
We noticed this empty building from the road in Shenzhen so we decided to explore. Thee were no signs saying "no entry," at least none that I could read. I think my scientist friend from Hong Kong could not understand the point especially as it was dangerous.. But every adventure requires a little danger.