At the top of the Oslo Opera house. You are not allowed cycle up here but I do it all the time.
Indeed I am the Strava “Local Legend” for the ride up there, since I have done it more than anyone else on Strava in the last 3 months
P.S. Ignore the average grade that Strava lists (-1.9%). Not sure where Strava pulls that from. It is actually more like 10+%. Here is a video from one of the times I rode up (@PedalSprell is filming).