I used to live in esbjerg, denmark in the first half of 2014. my bedroom's window was looking southwest, in the direction of north sea. i had a habit what was looking out the window for some minutes before i go to sleep. on that particular night (around 23:00) i was doing my usual "meditation stare" when something caught my attention around zenith. it looked like a square rotating around its center point, but only four white lights were visible on its four corners. regarding the size: it looked slightly bigger than full moon.
so it was rotating and moved about at a speed as an airliner would, when it sped up to an incredible speed in the direction of north sea. it was beyond the horizon maximum in one second. after that i waited a bit but it didn't came back. the whole sighting was no more than some seconds.
the window was open and i didn't hear any noise.