Petrinska Hostel was fantastic! It is located within easy walking distance of the train station, Wenceslas Square, and the Old Town. The double room was enormous with the most comfortable bed. The room and bathroom were both very clean. Someone even came in to make the bed and leave fresh towels each day which I've never seen in a hostel before. The room was very secure, requiring a key to enter the building, the suite (which included a few rooms, a kitchenette, and the bathroom), and then of course a separate key for the room. Even though the bathroom and kitchenette were shared with other rooms, we felt that we had complete privacy, and nights were very quiet for sleeping comfortably. We stayed for three nights and didn't want to leave. Do yourself a favor and stay here while in Prague!