There is a building under construction opposite my office. I saw this guy sleeping on the window frame of the 3rd floor. It is amazing how relaxed and peaceful this guy is in sleep when there is nothing preventing him from falling over. When I saw him, he was sleeping with his back towards me and then he turned around on the small platform he is sleeping on without ever appearing to be in the danger of falling down. The most dangerous way of sleeping I have ever managed is to sleep while standing in a crowded train.