My Watermark is Lake Ontario, only because I live so close to it.
I live in Ronson's Ville, so Lake Ontario is literally a four minute bike ride down. It is so pristine and beautiful because you are able to see the landscape change and the culture change from one end of Toronto to the other. From the Bluffs to Humber River. It's all so varied. It is also so important.
In the summer you can see that it brings life back to the city. We talk about water, but what it does for us and to us, both emotionally and physically is quite profound.
I lived in North York before, so there was no such thing as a lake near there, but then I moved down to the west-side of Toronto and have been walking by, hanging out, and sailing on Lake Ontario ever since.