Your own coordinates will be shown when you click on the "Details" option of your castle. In case you scrolled on the map and want to go back to your position, just look out for a red arrow at the edge of the screen. Clicking on it will fly you right back home.

In case you want to know in which zone you are, or how many fields need to be crossed to the next zone, click on your avatar. In the part "Rise to Power" you are shown all you need to know about zones and how close you are to the king.