Madrid goes to sleep late every night. Thus it also wakes up late next day. The underground starts at 6, and before that time the city is frighteningly empty. If you have a flight at 6:30, you have to take a bus to the airport, which operates from the central square all night only by sheer luck. Existence of other night buses is negligible, so you have to get to the central square by foot. So I went. I used this opportunity to have a look at the famous and always crowded in the daytime Paseo del Prado. In the night nothing disturbs its silence.