Yes I Do.At least it's a secret from the council.
My flat is owned by the local borough council. I pay rent to live here.
When I moved here many moons ago, what is now my Garden, was just rough grass and whatever weeds would grow in it. There was also a small tree in the middle of this 'Communal area'. After several years this became a medium sized tree with a massive and dense canopy, which completely shut out the sky from view, and with it most of the natural light from my flat. It took a cunning ploy by me to get that cut down. I got my doctor to write a letter stating that the lack of daylight caused by the dense canopy of the tree was causing me to become depressed. The council reversed their earlier decision that the tree would stay.
Access to my garden is via my back/living room door. There used to be an 18" drop from the back door onto six grey concrete paving slabs which constituted my patio.
It occurred to me one day that if there were ever a fire that prevented me from using the front door I had no other route of escape. I had actually had a series of wooden ramps over the years but these would eventually rot or just break up from use and the weather.
So I pointed this out to the council, and just for once, I got satisfactory action. Within two weeks I had the 8' foot square patio that is still there today, and for complicated reasons that I won't bore you with they built a path from the patio to the council path that now runs up the side of my garden, and because it was over three feet away from the wall I persuaded them to fill the gap with a raised bed. Huzzah!
Ok now we're getting to the secret garden bit.
When the work was finished I asked if I could A. have a pergola built over the new patio, and B. have a flowerbed running along the edge of the new path. The council guy said yes to the pergola, and yes, as long as it only extends a couple of feet into the Communal area to the flower bed.
Well I immediately got a gardener round to dig and plant me a 4' deep flowerbed along my new path.
That 4' flowerbed was the first incarnation of the 27' square garden that now forms the fourth incarnation of my garden.
Every few years or so, when the garden, always designed by a 'professional gardener' proved not to be working I've had it redone, and added a little more
of the communal area. The latest incarnation is the first that was designed by me, and even after only two seasons I know I've got it right.
You can see all of this if my explanation has left you wondering what the heck i'm talking about, in my photo's.
Now, the secret thing about my Garden, is the fact that officially it isn't there!.