iOS MapView add MKPointAnnotation which coordinate is (0, 0) not showing - ios

Question

I am trying to add annotations on MKMapView. The annotations can show up when the coordinates are not (0, 0), but when I set the annotation's coordinate as (0, 0), the annotation view can NOT show up.
On the iPhone XS simulator and device, only one annotation showing(location (10, 0)), the location(0, 0) not show up.
It seem that the (0, 0) annotation is add at the bottom of the map, not at the west side of Africa.
Any suggestion is appreciated.
- (void)viewWillAppear:(BOOL)animated {
[super viewWillAppear:animated];
// Add Annotation
MKPointAnnotation *annotation = [[MKPointAnnotation alloc] init];
annotation.coordinate = CLLocationCoordinate2DMake(0, 0);
[self.mapView addAnnotation:annotation];
MKPointAnnotation *annotationZero = [[MKPointAnnotation alloc] init];
annotationZero.coordinate = CLLocationCoordinate2DMake(10, 0);
[self.mapView addAnnotation:annotationZero];
}
#pragma mark - MKMapViewDelegate
- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id<MKAnnotation>)annotation {
if ([annotation isKindOfClass:[MKPointAnnotation class]]) {
static NSString *reuseIdentifier = #"map_annotation";
MKAnnotationView *annotationView = [_mapView dequeueReusableAnnotationViewWithIdentifier:reuseIdentifier];
if (annotationView == nil) {
annotationView = [[MKAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:reuseIdentifier];
}
annotationView.image = [UIImage imageNamed:#"annotation_icon"];
return annotationView;
}
return nil;
}

Answer 1

I started with a test using Swift and CLLocationCoordinate2DMake(0,0) worked fine, so the problem isn't related to a device but it is language specific issue.
You cannot use (0,0) in objective-c, instead use DBL_MIN, which is the smallest number possible, like so:
CLLocationCoordinate2DMake(DBL_MIN, DBL_MIN)