Martin ,,, we just want to be nosey and tick it off a list of ...well well i can do that after all :-)))
Have to wonder about some of the gradients on Strava, it shows Rundle St at 11.2% and a stretch of Anzac Hwy at 15.4%!
Perhaps roads with actual climbs might be more acurate
As Tim B has unearthed, start in Rundle St at 144 metres below sea level (underground tunnels????), head east to East Terrace, engage your compact gearing as there is a steep climb, not the 11.2%, but the killer, a massive 504.8% grade.