Pretty much all that they have said above is true! We always in the summer take a ride into Wasaga Beach, it is only about 20 mins or so away! It isn't what it used to be! There used to be a half decent waterpark there "Wasaga Waterworld" but was closed when we were there last year! There is another one about half hour away called Splash Canyon, but again geared more to kids. Elmvale Zoo is a nice, cheap zoo, and doesn't take all day. Again, about a 25 min ride or so! Alot of the little towns are cute and quaint.
Blue Mountain always seems to have something going on, so somedays we just hang around there during the day. We always stop and get maple taffy in snow, very tasty little snack! Nice area, the scenic caves, the tree top walk, the mini putt at the moutain top, are all fun things to do! Enjoy!