Try this where you get to the zoom that you want to animate the annotationViews:
for (MyAnnotation *annotation in myMapView.annotations)
{
MKAnnotationView *annotationView = [myMapView viewForAnnotation:annotation];
//Do your animation to the annotationView
//Example for fadeOut - fadeIn
[UIView animateWithDuration:0.5 animations:^{
annotationView.alpha = 0.2;
} completion:^(BOOL finished) {
[UIView animateWithDuration:0.5 animations:^{
annotationView.alpha = 1;
}];
}];
}
If you have all kinds of annotationView types and you want to animate just part of them, then you will need to check the type before the animation.