I've been to many "Pensao"s in Lisbon. I know they are not great quality, small old rooms with bathroom on the hall or with a shower in the room, rough beds and windows that don't always close properly. That's what you get for 25-35 eu/night in Lisbon. However, this one was an outstanding horrible experience!
Pensao Imperial is located right in Praca de Restauradores, a tall building covered in blue tiles, large sign, great central location. The pensao is actually only on the last floor, and you must walk up several dark dirty smelly stairs. The Pensao is separated from the rest of the building by a metal fenced door. Once you pay for your room (you must pay upfront), you do not get a key from this entrance. Each time you come in, you have to ring and obnoxious bell at the metal door. There were homeless people sleeping on the stairs and ringing the loud bell late at night!
We got a room with "a view" and "private bathroom" , meaning a sink... more