The place is pretty close to the old town (within 10 minutes walking distance). It is one of a unit within an old apartment building. Although the host made an honest effort to clean the place before hand... Let just say that the next time I m in Prague again, I would instead find a recently build hotel to stay in.
However, the place does has its old way charm, if you are into #jasonbourne feeling of a place, it will be perfect for you.