Since the depreciation of initCircularRegionWithCenter:radius:identifier:, how would you define the region to be monitored using CLLocationManager?
Since CLCircularRegion is a subclass of CLRegion, you can just cast the instance.
CLCircularRegion *region = [[CLCircularRegion alloc] initWithCenter:theCenter
radius:theRadius
identifier:theIdentifier];
// Then cast the instance for use with your CLLocationManager instance
[manager startMonitoringForRegion:(CLRegion *)region];