During the high school years at All Hallows' one building was a mystery, strictly off limits, out of bounds.
This, of course, made it immensely interesting. Forbidden fruit and all that.
The old convent was where secret Nun's business happened and we mere students were to know none of it.
I am sure whatever happened behind those imposing doors was distinctly uninteresting but the interest lay in the not knowing.
So when I saw the Mercy Centre (as it is now known) on the list of buildings taking part in Open House Brisbane 2013 I decided I had to go.
Unfortunately it will remain a mystery as only two rooms on the ground floor were open to the public. Poo, bum, wee.
But I did find the building is routinely open to visitors on Tuesdays and Wednesdays so all is not lost.
All was not lost today either. As we had made the effort to join the thousands of families traipsing around the city to see behind doors normally closed to the public it would have been churlish to let one small disappointment get in the way of a good time on a beautiful Sunday.
So off we hiked to the Customs House to peek inside the stately rooms and the far less stately cellars where the tariffs from passing vessels would have been collected in bygone days.
And then there was lunch and a mocktail on the terrace overlooking the river. Very nice too. I may be none the wiser as to the strange customs of the convent but those of Customs House have now been unlocked.