Como obter um endereço de coordenadas usando o MapKit?

Eu tenho esse código quando pressiona longamente o mapa que obtém as coordenadas:

func didLongPressMap(sender: UILongPressGestureRecognizer) {

    if sender.state == UIGestureRecognizerState.Began {
        let touchPoint = sender.locationInView(self.mapView)
        let touchCoordinate = self.mapView.convertPoint(touchPoint, toCoordinateFromView: self.mapView)
        var annotation = MKPointAnnotation()
        annotation.coordinate = touchCoordinate
        annotation.title = "Your position"
        self.mapView.addAnnotation(annotation) //drops the pin
        println("lat:  \(touchCoordinate.latitude)")
        var num = (touchCoordinate.latitude as NSNumber).floatValue
        var formatter = NSNumberFormatter()
        formatter.maximumFractionDigits = 4
        formatter.minimumFractionDigits = 4
        var str = formatter.stringFromNumber(num)
        println("long: \(touchCoordinate.longitude)")
        var num1 = (touchCoordinate.longitude as NSNumber).floatValue
        var formatter1 = NSNumberFormatter()
        formatter1.maximumFractionDigits = 4
        formatter1.minimumFractionDigits = 4
        var str1 = formatter1.stringFromNumber(num1)
        self.adressLoLa.text = "\(num),\(num1)"
                }
}

e eu quero imprimirannotation.title o endereço completo (rua, cidade, CEP, país).