The appartment was great and is nicely situated in Estoril near Cascais. But the following might be of relevance for renters.
The bed in the bedroom is 140cm which is too small for my wife and me. It is not very comfortable, especially the bed in the second room, which I was using. The neighbors in the appartement above are loud, they often go to bed not before 2. There is only one window in the living room which is to the north. So you do not recognize the sunny wheather until you go out. There was a smell in the bath, and rooftop construction work was done which was not mentioned in the description of the flat.