It was really nice flat with the river-view. It's really central. So yo can look everything in Porto by walking.
The interior is nice and really authentic with big windows, wooden floors and so on. It's a bit minimalistic but I like it.
There are some features which make this accommodation not a lot comfortable to stay by two couples. Because it's only one bedroom so one of you need to sleep on a sofa in leaving room (although the sofa is comfortable). Also it's only one bathroom and it's just next the door of the leaving room. But it wasn't a big problem.
You can come in by taking keys in special key-safe so it's comfortable especially if you arrive late, because you don't need to pay for late check-in.