I am a big fan of the Leslie Spit. My only regret was how long it took me to check it out while living in Toronto. I biked here with a friend before moving to the East End and I wish I biked here more often.
The first time I visited here I couldn't believe something like this existed in Toronto. An urban park that stretches out 5 km into the lake. It's created with construction waste and not only does it look good but it has fairly scientific uses as well. It's become a bid sanctuary and also helps shelter the city.
There are signs that say it's only open on weekends I believe but I've been in there during the week and there are some other people. And it's so peaceful because there are so few people at that time.
The only downsize is that the only washrooms you'll find are outhouses but they do exist. Also there is an area closer to the city that has a HUGE bird population and when you get closer to it you'Ll hear it and smell it. The bird sanctuary isn't smelly or noisy like that but the shelter there to watch the birds is covered in bird poop.
Great place to bike and take a stroll. Walking the whole thing would take a lot longer though. The trees also aren't large so there isn't tons of shade. Wear sunscreen! You can park near the entrance. A hot dog vendor is usually at the entrance on the weekend as well.