Me and my partner stayed at Mare Nostrum for one night as the hotel is not far from Athens airport. It is a huge hotel mainly for large tourist groups. Rooms are nice and we got upgrade if I am correct.
There is a huge pool area with possibility to get drinks, some food and just to enjoy the nice summer holidays. Tho sometimes it might get loud of all the animators noise.
Don’t go to swim in the sea, it is dirty and ugly, I could not even dive in there.More