A small grouping of islands just off the shores of Lake Ontario and Toronto Harbour, the Toronto Islands are a popular recreation destination for city locals that want to get away for a bit. Accessible by ferry, Centre and Algonquin Islands are the bigger and more frequented, although all islands are accessible by boat. You'll find variety between the islands, from residential neighborhoods on Algonquin and Ward's Islands to forested areas like (the apt) Forestry Island and Snake Island.
The greatest attraction is the fact that only maintenance automobiles are allowed on the island, so that you'll see mostly pedestrian and bike traffic. The beaches are also a highlight and are the best options available within the city limits; some notables are Ward's Island Beach, Island Beach, and Hanlon's Point Beach, the only clothing-optional beach in all of Ontario. These aren't your Mediterranean or equatorial beaches, but they're still great places to catch some sun, meet some people, and play volleyball in the Lake Ontario sand. For more info, consult the included site!