Some in the neighbourhood don't care too much for the proximity of the CAMH building, but one of the great consequences of having the mental health centre here is the park that comes along with it. There's no slides, no baseball diamonds, and no dogs. What does exist is quasi-quiet greenery and a few park benches allowing you to sit and enjoy the serenity.
Admittedly, if you are looking for parks with more facilities, there's Stanley Park (http://www.yelp.ca/biz/stanley-park-toronto) to the south, and Trinity-Bellwoods Park (http://www.yelp.ca/biz/trinity-bellwoods-park-toronto) to the east. This place is semi-walled in but still with public access allowing you to sit back, relax, and enjoy the day. It's a great place to find a quiet corner under one of the many shading trees, take out a book and savour the serenity.