Riksdagen - Swedish Parliament, Stockholm
Take a tour on the hop on/hop off sightseeing bus.
Of course it is just about the most touristy thing to do in any city. Still, we found out that if you don't have much time to spend, it is a good way to see the major points quickly.
The hop off/hop on system makes it easy to stay a little longer at sights that particularly interest you, while skipping the ones that you don't feel are so interesting.
The Swedish Parliament is called "Riksdag". It consists of 349 Members of Parliament. The building was built in the 1920s in modern style - even the glassy bulge was made in these times.
Swedish Parliment building is one of the most historical buildings and it is on a seperate 'Island'.