A day or two before, you can reserve a particular room or they can select one for you. I chose a room, making sure that it met our requirements, only to be told when we got there that they were putting us in another room, on a different floor, on the other side of the building. The air con didn't work, so with it being cold outside and the heating cranked up in the hotel, the room was unbearably warm at times. It was however clean, and within short distance of the main part of Salzburg.,