Stockholm's Central Terminal for bus, it is right across from Central Station which is for train.
If you are arriving at the Stockholm-Arlanda Airport (ARN), it is about 40KM (24Miles) to the Stockholm city center. You can either take the train for 290 SEK ($32) for 20 mins to Central Station, or take the bus (Flygbussarna) for 119 SEK ($13) for 45 mins to Central Terminal. The old city center (Gamla Stan) is about 1.1KM away
You also take the bus here to Nynäshamn färjeterminal, which is the Ferry terminal to Visby, Gotland. read more