On the stockholmtown website [in many ways excellent] this is only quoted as 10th in order of Stockholm's attractions. Extraordinary! I should put it top.
Ragnar Östberg, the architect combined some Italian design feature with what was called Sweden's National Romantic style and the result is stupendous.
At least one detester of guided tours - this one - is glad he went on this one and still would be even if it weren't the only way of gettimg in.
Anyway, where else would they call a red hall 'The Blue Hall?'