If your scale factor is 1, the entire circle is displayed.  If you use a larger scale factor, you will want the abililty to shift the circle around in its window, since the entire circle will no longer fit.  The 'Center on Origin' button on the right half of the control panel will place the center of your circle in the center of its window.  The 'Center on Selection' button directly below it will bring up a pop-up window from which you can select the location you wish to be placed at the center of the map window.

The "Center on Selection' button brings up this window.  Click within the circle to recenter your map, or use the yellow arrows in the upper right corner of the window to shift your view slightly.

Scaled map centered on origin:

Scaled map centered on selected location:

 

Another method exists to get more information about a crowded region on the circle.  Click on the location of interest, and a linear presentation of the designated genome region will be displayed in a new window.  For example, the following display was obtained by clicking in the vicinity of the coordinate 105,000 in 2+ Mbp genome.