Before we left the flat I wanted to vacuum because it is rather dusty. When I started the vacuum cleaner it made a loud noise and spouted out black smoke. It looked like the motor was actually burning, so I took it out on the balcony. That's when I saw this bird's nest with two eggs. The mother, which was a dove sat a few meters away waiting for me to go away. 
We left the flat as dusty as it was when we arrived...