very pretty to look at from the outside, just like the rest of the city!
I'm not sure the name is right, but it's good view
I can recomandate the guard change. BUT if you know the guard change in London, this will be a very funny thing for you.
Oslo's Royal Palace was built in the early 1800s on a hillside overlooking the harbor. It's fairly small, as far as palaces go. Surprisingly, visitors are allowed to walk completely around the building and practically up to the front door. Tours are offered during the summer. Plan to arrive during the changing of the guards, a low-key but interesting tradition. Then explore Slottsparken, the expansive surrounding gardens--you can picnic on the king and queen's front lawn.
The palace is on a hill over looking the center of the city. The guards outside, unlike in England, will chat with you and pose for photos.