Hi André,
Is this what you are looking for?
Manipulate[
Graphics[{EdgeForm[Black], LightGray,
CountryData[country, "Polygon"], PointSize[Large], Red,
Point[Reverse[CityData[#, "Coordinates"]]] & /@
CityData[{Large, country}]}, ImageSize -> {250, 250}], {country,
CountryData[] // CanonicalName, ControlType -> PopupMenu}]