This is the largest city park in central Etobicoke and also borders Mississauga both to the north and west.
This park has a variety of sports related facilities and buildings including a ski chalet, pool and gymnasium facilities (Etobicoke Olympium), ice arena, stadium with field for track, football, soccer, and softball. There are also go karts and golf course as well as the conservatory which is a large greenhouse.
Centennial hill is a large man made mound close to the middle of the park. It is sort of hard to miss considering it's a hill while everything else around is pretty flat. This hill if I recall correctly was made of landfill a very long time ago. It's used for sledding and skiing in the winter months.
I took swimming lessons at the Olympium a couple years ago but it was closed a while ago because of renovations they are making in preparations for the Pan Am games in 2015.
Every Canada Day long weekend Centennial Park is the site for Toronto's Rib Fest. This is when the park gets really packed and the event is very popular so the local streets become quite busy.
There is a very large picnic area near the Rathburn side and a pond that I used to go fish years ago. I believe back in the day it was stocked with bass but I don't know if they still do that.
TIP: the main road to access this park from any of the highways is Rathburn Road from the 427 or Renforth Drive from the 401. Both of these streets towards the park are both only 40km/h. Renforth especially looks like a 60 km/h road but it's only 40 as there are multiple schools on Renforth and Rathburn too.