The RS Scandinavia guidebook directions to Stadhuset ( “300 yards behind the Central Train Station- about a 15 minute walk from either the station or Gamla Stan”) are not helpful in the least. In fact, they could really eat up your time. What’s up, guidebook writers???
This, from the City of Stockholm website, got us there very quickly and efficiently. We used the second option.
The two metro stations closest to the City Hall is T-centralen or Rådhuset.
If you get off at T-centralen, walk towards Centralstationen and use exit Vasagatan. Walk south along Vasagatan towards Tegelbacken. Turn right underneath the bridge.
If you get off at Rådhuset, use exit Hantverkargatan/Stadshuset Turn left on Hantverkargatan.