There are several map view modes on Silverlight Bing Maps as 2D projection of the Earth. Road, Aerial or AerialWithLabels modes.

In Aerial mode we are only able to see landform on the map, there are no roads, street names and place names. 

we can define Map Mode in XAML code with "Mode" Property

<Microsoft_Maps_MapControl:Map Mode="Aerial" x:Name="MapIK" Center="41,29" ZoomLevel="10"/>

or define dynamicly in C#

MapIK.Mode = new AerialMode();

 
All the best