MapLayer layer1 = new MapLayer();

        Pushpin pushpin1 = new Pushpin();
        pushpin1.GeoCoordinate = new GeoCoordinate(51.503147, -0.113245);
        pushpin1.Content = "Pin 1";

        MapOverlay overlay1 = new MapOverlay();
        overlay1.Content = pushpin1;
        overlay1.GeoCoordinate = new GeoCoordinate(51.503147, -0.113245);
        layer1.Add(overlay1);

        WC_WATMap.Layers.Add(layer1);