In Silverlight Bing Maps application, we can set our map view to any location on the world with changing by Location coordinate; Latitude and Longtitude values.

Set Location for Istanbul in XAML
we can set Center property in Map Control with center point of the map by the location coordinate

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

We can set this location dynamicly C# code

First we should add using Microsoft.Maps.MapControl reference.

Location Istanbul = new Location(41, 29);
MapIK.Center = Istanbul;
MapIK.ZoomLevel = 8;

All the best.