Its important to note that there are several hotels/ hostels in Arequipa with the name Casa Blanca so check the address before you go!
We stayed Puente Bolognesi, which is directly on the corner to the main square (plaza de armas) so it couldnt be more central. Some of the rooms have a balcony looking over to the square! The place is build beautifully of the original white stone which still features in the rooms. We stayed in two different rooms, both where spacious and had a balcony, spotless clean, TV, and private bathrooms with hot shower. Really nice beds and comfortable. Rooms towards the street are a little noisy with the traffic at night at the square but it didnt bother me.
The hotel also has a big common room on the second floor with a little view over the town.
In general very well maintained and clean. They have 8 rooms.
Services was great two, the guys at the reception were really helpful and friendly with all our questions. Only one of the girls was a bit moody and constantly distracted on the phone to her friends.. we were able to store our luggage at the hotel when we went for a trip, and breakfast is included as well (its only contintental breakfast so just coffee, juice, jam.. a little thin for the price but still good standard). There is a big kitchen upstairs but I dont know if it can be used by guests. Sheets and towels were included as well.
It calls itself Hostal but in general more run like a hotel.
I loved it and would really recommend it to everyone!
