Papillon Hotel is situated on the Buda side of the Danube river, in a quite area, about 10 min walk from nearest tram station.
The entrance hall is small and you have to pass through a narrow corridor and up the stairs before you reach the reception desk. However, the staff is very friendly and good in English, and the rooms are clean and nice.
This is a very good alternative in the budget class (55 euros / night for a double room).