-(IBAction)foundTap 
UITapGestureRecognizer *)recognizer
{
CGPoint point = [recognizer locationInView:self.mapView];
CLLocationCoordinate2D tapPoint = [self.mapView convertPoint:point toCoordinateFromView:self.view];
[self pointInsideOverlay:tapPoint];
if (isInside)
{
....
}
}
Here is a method to call from the previous to check if the point is inside the overlay:
-(void)pointInsideOverlay CLLocationCoordinate2D )tapPoint
{
isInside = FALSE;
MKPolygonView *polygonView = (MKPolygonView *)[mapView viewForOverlay:polygonOverlay];
MKMapPoint mapPoint = MKMapPointForCoordinate(tapPoint);
CGPoint polygonViewPoint = [polygonView pointForMapPoint:mapPoint];
BOOL mapCoordinateIsInPolygon = CGPathContainsPoint(polygonView.path, NULL, polygonViewPoint, NO);
if ( !mapCoordinateIsInPolygon )
//we are finding points that are inside the overlay
{
isInside = TRUE;
}
}