You can use CLGeocoder geocodeAddressString method. It will return an array of CLPlacemark objects that contain gps coords and city, location info.

        let address = "Burlington, Vermont"
        CLGeocoder().geocodeAddressString(address, completionHandler: { placemarks, error in
            if (error != nil) {
                return
            }

            if let placemark = placemarks?[0]  {
                let lat = String(format: "%.04f", (placemark.location?.coordinate.longitude ?? 0.0)!)
                let lon = String(format: "%.04f", (placemark.location?.coordinate.latitude ?? 0.0)!)
                let name = placemark.name!
                let country = placemark.country!
                let region = placemark.administrativeArea!
              print("\(lat),\(lon)\n\(name),\(region) \(country)")
            }
        })
    }

To go the other way, from GPS coords use reverGeocodeLocation method

let lat = 12.000
let lon = 34.000
if let loc = CLLocation(latitude: lat, longitude: lon) as? CLLocation {
                CLGeocoder().reverseGeocodeLocation(loc, completionHandler: { (placemarks, error) in
                    if let placemark = placemarks?[0]  {
                        let lat = String(format: "%.04f", (placemark.location?.coordinate.longitude ?? 0.0)!)
                        let lon = String(format: "%.04f", (placemark.location?.coordinate.latitude ?? 0.0)!)
                        let name = placemark.name!
                        let country = placemark.country!
                        let region = placemark.administrativeArea!
                        print("\(lat),\(lon)\n\(name),\(region) \(country)")
                    }
                })