A very cute and affordable hostel in the centre of Lisbon's shopping district with easy access to anywhere in the whole city. At first it is a little difficult to get to, with lots of stairs all the way up the hillside to where it is located. There is actually an elevator via the Pingo Doce supermarket, which the staff will explain to you once you're checked in. I think sending this info out before people arrive would be helpful.
I felt really at home here. I could cook a full meal, talk to all the staff comfortably, and felt secure in the area. My only complaint is that there's a lot of squeeky noises, the neighbours bang about a lot, and the radiators in the room emit a clanging sound sometimes. Other than these interruptions to sleep (and bare in mind it is a shared room hostel) I could not say anything bad about This Is Lisbon. I think it's a great choice for travellers to get to know the city from right in the centre.
I'll recommend people stay here - all ages and ethnicities are constantly travelling through the doors. Just be prepared for uphill walking to get to the hostel so bare it in mind if you have issues walking.