Worse kept secret for east end 905ers is Unionville Main Street and Too Good pond park, actually for a while most Main Street goers didn't even know there was a park a few blocks away.
I believe I visit this park weekly in the Summer, just a great place to go for a walk and grab some Starbucks. It's also has become somewhat of a people and car watching street now, similar to Yorkville.
In the winter, a few brave people take to the ice to skate and play pond hockey, tons of fun and surreal when you remember in the summer that your're actually on the pond you overlook.
This would be 5+ stars if they had paddle boats for rental but I think it's a protected pond.