The Castle Hotel is located on a side street, and you are right around the corner from the action. Everything is very easy to reach on foot, and the walk to/from the Aircoach bus (external airport transfer, approx. 11 euros per person) is only a few minutes away.
The rooms have their typical charm (I like that a lot), perhaps a bit worn, but clean and everything necessary is provided. The bed was also great. Even though the doors are a bit thin, only some tourists are loud there, stomping through the hallways at 2 or 3 in the morning, talking loudly, and slamming doors...
The staff is very friendly and accommodating. The (continental) breakfast is delicious and sufficient, 2 coffee machines are available and there is also hot, delicious cocoa. We even received a small packed lunch for a day trip.
There is also a cozy terrace where you can enjoy breakfast, a drink in the evening, or something from the "bar menu." There is live music every day, which you can also hear on the terrace (the bar is in the basement).
All in all, highly recommended; I would definitely stay there again.