First, the corridors near the rooms had a very unpleasant smell.
Second, and this was the main reason for my low rating, on our first night—while we were asleep—someone opened our room door and entered, despite the door being locked and a “Do Not Disturb” sign placed outside. We woke up terrified. I immediately went outside to see who it was and found a man who said he was from the reception.
I later followed him downstairs to ask for an explanation. He apologized and claimed there was a mistake in the booking system, saying the room was shown as not equipped or unoccupied. This explanation was not convincing. As a result, for the rest of our stay, we felt unsafe and had to place a chair and our luggage behind the door every night.