The back to back house is down a small little side street close to the centre of town. It is clean and stylish and just perfect for two of us on a girls weekend. It only ever took us 5 minutes to get to where we were going walking, and there were plenty of great restaurants and bars nearby to keep us busy.
The only couple of minor downsides to the house are that the 2nd bedroom has no windows and therefore no natural light. and the surrounding houses were quite noisy when we were there, it looked like the house opposite was a student house and we could hear talking and singing well into the night. As a caveat to the noise issue, we were also there on the weekend of FC Porto winning the Portugese league and the city was in party mode so we could have just been unlucky with this.