Temple Hall Farm Regional Park is a great place for small kids, but it is way off the beaten track. To get there, you have to get off the Leesburg Bypass (Rt. 15) onto a gravel country road and drive for a mile or two before coming upon the farm. But it is worth the effort. This working farm is free, and you will see peacocks, llamas, pigs, sheep, cows and even some oxon. The park also features a playground and picnic areas.
From late September through early November, the park hosts a giant corn maize (24-acres!), as well as pig races, pony rides, a cow train, giant jumping pillows (like a moonbounce with no top), pumpkin blasters (shoot pumpkins at targets), hayrides, pick your own pumpkin patch, and more. The cost for this annual Corn Maize and Fall Festival is $12 for those over the age of 12, $10 for ages 3-11, and free for those 2 and under.