Is there way to limit MKMapView maximum zoom level?

Use this example to lock the maximum zoom range, also equally you can limit the minimum

map.cameraZoomRange = MKMapView.CameraZoomRange(maxCenterCoordinateDistance: 1200000)

If you are targeting iOS 13+, use the MKMapView setCameraZoomRange method. Simply provide the min and max center coordinate distances (measured in meters).

See Apple's Documentation here: https://developer.apple.com/documentation/mapkit/mkmapview/3114302-setcamerazoomrange

The following code worked for me and is conceptually easy to use because it sets the region based on a distance in meters. The code is derived from the answer posted by: @nevan-king and the comment posted by @Awais-Fayyaz to use regionDidChangeAnimated

Add the following extension to your MapViewDelegate

var currentLocation: CLLocationCoordinate2D?

extension MyMapViewController: MKMapViewDelegate {
    func mapView(_ mapView: MKMapView, regionDidChangeAnimated animated: Bool) {
        if self.currentLocation != nil, mapView.region.longitudinalMeters > 1000 {
            let initialLocation = CLLocation(latitude: (self.currentLocation?.latitude)!,
                                         longitude: (self.currentLocation?.longitude)!)
            let coordinateRegion = MKCoordinateRegionMakeWithDistance(initialLocation.coordinate,
                                                                  regionRadius, regionRadius)
            mapView.setRegion(coordinateRegion, animated: true)
        }
    }
}

Then define an extension for MKCoordinateRegion as follows.

extension MKCoordinateRegion {
    /// middle of the south edge
    var south: CLLocation {
        return CLLocation(latitude: center.latitude - span.latitudeDelta / 2, longitude: center.longitude)
    }
    /// middle of the north edge
    var north: CLLocation {
        return CLLocation(latitude: center.latitude + span.latitudeDelta / 2, longitude: center.longitude)
    }
    /// middle of the east edge
    var east: CLLocation {
        return CLLocation(latitude: center.latitude, longitude: center.longitude + span.longitudeDelta / 2)
    }
    /// middle of the west edge
    var west: CLLocation {
        return CLLocation(latitude: center.latitude, longitude: center.longitude - span.longitudeDelta / 2)
    }
    /// distance between south and north in meters. Reverse function for MKCoordinateRegionMakeWithDistance
    var latitudinalMeters: CLLocationDistance {
        return south.distance(from: north)
    }
    /// distance between east and west in meters. Reverse function for MKCoordinateRegionMakeWithDistance
    var longitudinalMeters: CLLocationDistance {
        return east.distance(from: west)
    }
}

The above snippet for MKCoordinateRegion was posted by @Gerd-Castan on this question:

Reverse function of MKCoordinateRegionMakeWithDistance?