How about a leisurely hike on the walking trails at a nearby Provincial Park?
Picnic at a nearby lake. Bring your bathing suits and towels and make a day of it.
Picnic at a park. Bring your frisbee or a ball and glove.
Take in some of the small town summer festivals. Wander around some of the farmers markets. Go to a Pick Your Own farm and, well, pick your own.
None of these cost much more than the price of gas.