The commuter train station, Arlanda C, is located between terminals 4 & 5. The trip takes 43 minutes and costs SEK 125. If you buy a SL Card (good for all subways, commuter trains, buses and some ferries) there is only a SEK 75 surcharge. Södra Station (Swedenborgsgatan exit) is located just 4 blocks from The Rival Hotel. Turn left onto Swedenborgsgatan and continue to Mariatorget square. Trains depart twice an hour.